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The U.S. aluminum industry generates nearly $71 billion a year in direct economic impact. When all suppliers and related business functions are taken into account, the industry drives $174 billion in economic impact- almost 1 percent of GDP.

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Natural Medicine is Great, but Chemists Can Make It Even Better - The Conversation

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Natural Medicine is Great, but Chemists Can Make It Even Better - The Conversation

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Take one plant, tweak it a little... Cifor, CC BY-NC

For years humans have searched for medicines in nature. While some seek "natural cures" in order to avoid chemicals, in truth everything is made up of chemistry. But as humans, we're very good at manipulating what we find in nature - either through intention or accident.

Penicillin: the antibiotic game changer

The late American anthropologist George Armelagos showed 30 years ago that the inhabitants of ancient Nubia made their beer by fermenting grain that contained streptomyces bacteria, which produces the antibiotic tetracycline. This in turn led to very low levels of infectious disease in the population.

But it wasn't until the accidental discovery of penicillin by Alexander Fleming in 1928 and work done by Howard Florey and Ernst Chain in 1940 that led to the treatment of many wounded soldiers in World War II that the story of modern antibiotics really began.

There are many different molecules in the penicillin family - for example, Penicillin G, the substance made by Florey and Chain, contains 41 atoms. But all of them have the same core made up of two rings of atoms - mainly carbon atoms - fused together. Different molecules have different properties. One drawback of penicillin G was that it was broken up by stomach acid and could only be administered by injection.

But penicillin is manufactured by fermentation, and chemists found that they could produce penicillins with slightly different structures by changing the chemicals added to the fermenting broth. Different structures allowed researchers to produce penicillin, for example, that was stable to acid and allowed it to be taken by mouth.

It also subsequently became possible to mass-produce 6-aminopenicillanic acid - the molecule at the heart of the penicillin structure - and to then add side-chains of extra atoms to design a particular penicillin, like one that could tolerate threatening bacteria enzymes. This process is known as semi-synthesis - using the molecular structure from a natural source before adding "finishing touches".

After the discovery of penicillin, there was intense interest in finding new antibiotics. The discovery of a molecule called chlorotetracycline (Aureomycin) in a sample of Missouri soil in 1945 led to a whole family of tetracycline antibiotics. These now semi-synthetic products include doxycycline, effective against Lyme disease and anthrax.

Invermectin: the golf course find

The 1970s yielding another important discovery from a microorganism named Streptomyces avermectinius, found in a soil sample from a seaside golf course by Japanese scientists. From this they isolated a molecule called avermectin, which proved active against numerous parasites. Still not satisfied, researchers made small tweaks to its structure to make it even more active. By dint of adding just two hydrogen atoms (to a carbon-carbon double bond) they created ivermectin.

Ivermectin is a tremendous success story in the treatment of river blindness (onchocerciasis), a scourge of communities in tropical regions in the Americas and sub-Saharan Africa. This disease is due to a parasitic worm Onchocerca volvulus and is spread by certain black flies. A single dose of ivermectin every six months for the life cycle of the worms can keep the parasite at bay.

Artemisinin: standing the test of time (just)

An even greater scourge of sub-Saharan Africa is malaria, and the great discovery in the past half-century has been artemisinin, obtained from the Chinese herb Artemisia annua. Artemisinin itself is not easily absorbed by the body so chemists have slightly altered its molecular structure and created new molecules - this is semi-synthesis at work again.

These have very similar structures to artemisinin but are more effective agents called arteether or artesunate. The latter of these can be administered intravenously for rapid action so is used against acute cerebral malaria where the disease spreads rapidly to the brain and can be fatal within three days.

But chemists can't be complacent - the genes of the malaria parasite have shown an ability to adapt to become resistant to artemisinin. And as one of the most effective remaining antimalarial drugs, resistance is a serious problem.

Aspirin: the daddy of semi-synthetic

And the daddy of all semi-synthetic drugs is aspirin. Back in the 18th century, an Oxfordshire clergyman named Edward Stone pioneered the use of willow bark in treating fevers; the bark contained a molecule called salicin, which in the body is transformed into the active compound, salicylic acid.

By the 1870s, salicylic acid itself was being used to treat fevers and pain, but digestive problems and ulcers were associated with its use. So chemists working for the German company Bayer converted it to acetylsalicylic acid, known today as aspirin, and that rapidly became the medicine of choice as an anti-inflammatory and painkiller.

Nature is the best synthetic chemist there is. It creates unbelievable molecules - both penicillin and artemisinin contain groupings of atoms that chemists thought could not exist - but they show that chemists can still improve on nature's bounty and make amazing molecules that work even better in treating human ailments.

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Natural medicine is great, but chemists can make it even better

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For years humans have searched for medicines in nature. While some seek "natural cures" in order to avoid chemicals, in truth everything is made up of chemistry. But as humans, we're very good at manipulating what we find in nature - either through intention or accident.

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Aspirin - Turn of the Century Miracle Drug - Science History

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Aspirin - Turn of the Century Miracle Drug - Science History

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Aspirin: Turn-of-the-Century Miracle Drug | Science History Institute

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Aspirin has had a long history as a pain reliever—2,000 years of history. But only in the 1970s did scientists begin to uncover its chemical secrets.

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Aspirin or acetylsalicylic acid is a derivative of salicylic acid. It is a mild, non-narcotic analgesic that's useful in the relief of headache as well as muscle and joint aches. The drug works by inhibiting the production of body chemicals known as prostaglandins, which are necessary for blood clotting and for sensitizing nerve endings to pain.

Early History

The father of modern medicine was Hippocrates, who lived sometime between 460 B.C and 377 B.C.

Hippocrates left historical records of pain relief treatments that included the use of powder made from the bark and leaves of the willow tree to help heal headaches, pains and fevers. However, it wasn't until 1829 that scientists discovered that it was a compound called salicin in willow plants that relieved the pain.

In "From A Miracle Drug" Sophie Jourdier of the Royal Society of Chemistry wrote:

"It was not long before the active ingredient in willow bark was isolated; in 1828, Johann Buchner, professor of pharmacy at the University of Munich, isolated a tiny amount of bitter tasting yellow, needle-like crystals, which he called salicin. Two Italians, Brugnatelli and Fontana, had in fact already obtained salicin in 1826, but in a highly impure form. By 1829, [French chemist] Henri Leroux had improved the extraction procedure to obtain about 30g from 1.5kg of bark. In 1838, Raffaele Piria [an Italian chemist] then working at the Sorbonne in Paris, split salicin into a sugar and an aromatic component (salicylaldehyde) and converted the latter, by hydrolysis and oxidation, to an acid of crystallised colourless needles, which he named salicylic acid."

So while Henri Leroux had extracted salicin in crystalline form for the first time, it was Raffaele Piria who succeeded in obtaining the salicylic acid in its pure state. The problem, though, was that salicylic acid was hard on the stomach and a means of "buffering" the compound was needed.

Turning an Extract Into Medicine

The first person to achieve the necessary buffering was a French chemist named Charles Frederic Gerhardt.

In 1853, Gerhardt neutralized salicylic acid by buffering it with sodium (sodium salicylate) and acetyl chloride to create acetylsalicylic acid. Gerhardt's product worked but he had no desire to market it and abandoned his discovery.

In 1899, a German chemist named Felix Hoffmann, who worked for a German company called Bayer, rediscovered Gerhardt's formula. Hoffmann made some of the formula and gave it to his father who was suffering from the pain of arthritis. The formula worked and so Hoffmann then convinced Bayer to market the new wonder drug. Aspirin was patented on February 27, 1900.

The folks at Bayer came up with the name Aspirin. It comes from the "A" in acetyl chloride, the "spir" in spiraea ulmaria (the plant they derived the salicylic acid from) and the "in" was a then familiar name ending for medicines.

Before 1915, Aspirin was first sold as a powder. That year, the first Aspirin tablets were made. Interestingly, the names Aspirin and Heroin were once trademarks belonging to Bayer. After Germany lost World War I, Bayer was forced to give up both trademarks as part of the Treaty of Versailles in 1919.

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Hippocrates Discovered Aspirin (He Just Didn't Know It)

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Aspirin or acetylsalicylic acid is a derivative of salicylic acid. It is a mild, non-narcotic analgesic that's useful in the relief of headache as well as muscle and joint aches. The drug works by inhibiting the production of body chemicals known as prostaglandins, which are necessary for blood clotting and for sensitizing nerve endings to pain.

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Get access to files anywhere through secure cloud storage and file backup for your photos, videos, files and more with Google Drive.

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NOVA - Percy Julian: Forgotten Genius - Making Cortisone From Plants - PBS Learning Media

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NOVA - Percy Julian: Forgotten Genius - Making Cortisone From Plants - PBS Learning Media

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NOVA: Percy Julian: Forgotten Genius | Making Cortisone From Plants | PBS LearningMedia

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Learn about chemist Percy Julian's work to synthesize cortisone. Julian's work made cortisone-a steroid used to treat rheumatoid arthritis-more easily accessible to millions of patients. Julian knew from earlier studies that plants and animals produced steroids with the same carbon-ring structure, so he isolated large quantities of molecules that closely resembled human cortisone from a cheap and abundant plant source-soybeans.

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Percy Lavon Julian

Julian, Percy Lavon 1899-1975

Chemist
Determined to Succeed in the Face of Racism A Groundbreaking Achievement Produced Synthetic Cortisone from Soybeans Established His Own Pharmaceutical Company
Known as the soybean chemist for his extraordinary success in synthesizing innovative drugs and industrial chemicals from natural soya products, Percy Lavon Julian was an internationally acclaimed scientist whose discoveries earned him more than 130 chemical patents and a host of professional awards. Among his most important contributions were the creation of a synthetic version of cortisone, a drug used to relieve the pain and inflammation of rheumatoid arthritis, and physostigmine, prescribed to alleviate the effects of glaucomaa disease of the eye that can cause blindness if left untreated. Julians work with soybeans and soya derivatives also led to the mass production of the male and female hormones testosterone and progesterone and the development of a powerful firefighting chemical called Aero-Foam, used by the U.S. Navy during World War II. The first African American to direct a modern industrial laboratory, he spent 17 years with the Glidden Company in Chicago before leaving to establish his own successful pharmaceutical enterprise, Julian Laboratories, Inc.

In addition to his groundbreaking work in the field of organic chemistry, Julian was a leader in the fight for civil rights. A strong supporter of Dr. Martin Luther King, Jr., and the Southern Christian Leadership Conference, in 1967 he joined a group of 46 other black businesspeople in raising money to enforce civil rights legislation through the NAACP Legal Defense and Educational Fund. Despite his personal and professional success, Julians own encounters with racismfrom the college professors who refused to offer him a teaching assistantship to the hoodlums who firebombed his suburban homewere never far from his mind.

The eldest of six children, Percy Lavon Julian was born in Montgomery, Alabama, in 1899. His father, James, who worked as a railway mail clerk, was the son of former slaves who went on to purchase their own small farm. According to Percys younger brother, Emerson, James Julian was a strict disciplinarian who had high expectations for his children. All six would later earn advanced degrees. One day, Emerson recalled, Percy rushed home from elementary school expecting to be congratulated for having received a score of 80 on an arithmetic exam. Instead of praising him, the elder Julian responded with disappointment, stating that anything less than 100 percent would never do. Julian took his fathers advice seriously and went on to graduate at the top of his class from the State Normal School for Negroes. He then entered Indianas DePauw University with the hope of studying organic chemistry. There he excelled in both his studies and

Born April 11, 1899, in Montgomery, AL; died of cancer, 1975; son of James S. (a railway mail clerk) and Elizabeth Lena (Adams) Julian; married Anna Johnson (a sociologist), December 24, 1935; children: Percy Lavon, Jr., Faith Roselle, Rhoderic Education: DePauw University, B.A, 1920; Harvard University, M.A., 1923; University of Vienna, Ph.D., 1931.

Chemistry instructor, Fisk University, 1920-22; Harvard University, research assistant in chemistry, 1925-26; professor of chemistry, West Virginia State College for Negroes, 1926-27; Howard University, associate professor and acting head of chemistry department, 1927-29, professor and department head, 1931-32; research fellow and teacher of organic chemistry, DePauw University, 1932-36; Glidden Company, Chicago, director of research, soya-products division, 1936-45, research director and manager of fine chemicals development, 1945-53; president, Julian Laboratories, Inc. and Laboratorios Julian de Mexico, 1953-64; president, Julian Associates, and director, Julian Research Institute, 1964-75. Head of Council for Social Action of the Congregational Christian Churches, 1956; special consultant, National Institute of Arthritis and Metabolic Diseases; member of board, NAACP Legal Defense and Educational Fund, Center for the Study of Democratic Institutions.

Member: Phi Beta Kappa; National Academy of Science; fellow, Chemical Society of London, New York Academy of Science, and American Institute of Chemists.

Selected awards: Spingarn Medal, NAACP, 1947; Chicagoan of the Year, Chicago Sun-Times, 1950; Silver Plaque Award, National Conference of Christians and Jews, 1965; Chemical Pioneer Award, American Institute of Chemists, 1968; Procter Prize, 1974; inducted into National Inventors Hall of Fame, 1990; commemorative stamp issued by U.S. Postal Service, 1993.

extracurricular activities and in 1920 was named valedictorian of his graduating class.

He soon discovered, though, that academic achievement and leadership qualities were not enough to guarantee him a place in graduate school. For a week Julian waited anxiously while his fellow students received offers of graduate fellowships at some of the countrys leading universities. Finally he could stand the suspense no longer and went to the home of his mentor, Dr. William Blanchard, who reluctantly showed him a handful of letters he had received from chemistry professors around the country. According to an article in Ebony, all of the correspondence advised Blanchard to discourage his bright colored lad from pursuing graduate study in the field. We couldnt get him a job when hes done, and itll only mean frustration, one professor had written. Why dont you find him a teaching job in a Negro college in the South? He doesnt need a Ph.D. for that. In Many Shades of Black, published nearly half a century later, Julian recalled his pain and anger upon learning that all of his hard work had come to nothing. There went my dreams and hopes of four years, and as I pressed my lips to hold back the tears, I remembered my breeding, braced myself, and thanked him [Dr. Blanchard] for thinking of me, he wrote.

Although Julians father advised him to give up the idea of a career in chemistry to enter medicine, a field which offered more opportunities for blacks, Julian was determined to persevere in his chosen course of study. Louis Haber, writing in Black Pioneers of Science and Invention, traced the fledgling chemists interest in the subject back to a boyhood incident: ever since the day when, as a small child, he had peered through the window of an all-white high school to watch a group of boys at work in a chemistry lab, Julian had wanted to be a chemist. After graduating from DePauw, he took the advice of his professors and accepted a teaching position at Fisk University, a black college in Tennessee. Two years later he was awarded an Austin Fellowship to continue his graduate studies at Harvard. He received his masters degree in chemistry in 1923.

Students of Julians academic rank were ordinarily offered the opportunity to serve as teaching assistants. But according to Paul de Kruif of Readers Digest, the powers-that-be at Harvard felt that because Julian was black, Southern white students might not accept him as a teacher. He remained at Harvard for the next several years under a series of minor research fellowships, waiting on tables, stoking coal, and working at a variety of other part-time jobs in order to make ends meet. In 1926 he accepted a teaching position at the West Virginia State College for Negroes but was so disillusioned by the lack of facilities and intellectual stimulation that he left after only one year. The following year he was offered the position of acting head of the department of chemistry at Howard University in Washington, D.C. He remained there for two years, during which time he helped to plan and oversee the construction of a new, $1 million chemistry lab.

Julian interrupted his teaching career in 1929 when he was awarded a General Education Board Fellowship to continue his graduate studies at the University of Vienna. There he worked side by side with the eminent Viennese chemist Ernst Spath, who had won wide recognition for his synthesis of the drugs nicotine and ephedrine. Like Spath, Julian was intrigued by the ways in which nature converted simple organic compounds into complex substances, such as vitamins and hormones. In an effort to supplement the limited supply of chemical riches produced by plants and animals, the two worked tirelessly to duplicate these patterns of natural conversion in the laboratory. In so doing, they helped to advance the bold, new frontiers of synthetic chemistry.

Among Julians many areas of investigation was the soybean, a product which was then being used in Germany for the manufacture of a variety of drugs, including physostigmine. Physostigmine, originally isolated from the seeds of the Physostigma plant in 1865, causes the pupil of the eye to contract and is thus useful in the treatment of glaucoma. If untreated, glaucoma causes pressure within the eyeball to increase to such an extent that the retinathe light-sensitive layer that lines the interior of the eyeis destroyed, resulting in blindness. In the early 1930s, scientists did not understand why physostigmine reduced pressure within the eye, nor were they able to obtain sufficient quantities from nature to provide patients with the treatment they needed.

After receiving his Ph.D. from the University of Vienna in 1931, Julian returned to the United States to continue his career in teaching. He spent one more year at Howard University, and then, at the invitation of his former professor, Dr. Blanchard, returned to DePauw University as a research fellow and teacher of organic chemistry. At Howard, Julian, together with two of his colleagues from Vienna, had begun an extensive investigation into the structure and synthetic production of physostigmine. When Julian moved to DePauw in 1932, Dr. Blanchard, then dean of the college, arranged for a special laboratory to be designed and equipped for him. At the lab, Julian, the Viennese chemist Dr. Josef Pikl, and six graduate students buried themselves in their research. Before long, their work on the synthesis of physostigmine, much of which was published in monograph form in the Journal of the American Chemical Society, had attracted the attention of the international scientific community. Finally, in 1935, Julian and Dr. Pikl succeeded in producing an exact synthetic replica of physostigmine. Their discovery was hailed by scientists from around the world and the details published in a host of scholarly texts and journals.

Despite his momentous accomplishments in the laboratory, Julian continued to encounter racial prejudice within the academic community. Upon completion of his groundbreaking work with physostigmine, Dean Blanchard recommended that Julian be named head of the chemistry department at DePauw. This would have made him the first African American chemistry professor at a predominantly white American university. But Blanchards colleagues immediately objected to the suggestion, claiming that the appointment would be ill-advised.

Around the same time, the Glidden Company, one of the countrys largest paint, varnish, and chemical manufacturers, was seeking a research chemist to direct a study of the protein-rich soybean. Hearing of Julians achievements, Gliddens vice-president contacted him and offered him the position of chief chemist and director of the companys soya-products division. Worn out by racial conflict in the academic world and eager to face a new challenge, Julian accepted immediately. Nine years later he was named director of research and manager of fine chemicals development. Never before had a black man served in so esteemed a position within the firm, wrote Hamilton Bims in Ebony. The association lasted some 17 years, and Dr. Julian was idolized by his employers and subordinates.

Julians first project at Glidden was to devise a technique for coating paper using soya protein in place of a more expensive milk protein. Some years later the same soya protein was used in the manufacture of Aero-Foam, a firefighting solution that extinguished oil and gasoline fires by forming an impenetrable blanket over them. According to Haber, the solution, which was nicknamed bean soup, helped save the lives of thousands of sailors and naval airmen during World War II. Julians research with soybeans also resulted in an innovative technique for manufacturing synthetic hormones. Hormone deficiency, which often occurs in people of advancing age, can result in cancer, extreme fatigue, and a variety of other medical problems. Although many hormones can be found in sterolsor solid alcoholsproduced by certain animals and vegetables, these sterols are often difficult to extract, or available in very short supply. Using a chemical solvent made of quicklime and plaster of Paris, Julian devised an effective method of extracting sterols from soybean oil. His work resulted in a tremendous increase in the world supply of synthetic progesterone and testosterone, as well as a significant reduction in the cost of hormone treatments.

Another of Julians crowning achievements at Gliddenperhaps the most important of his careerwas the synthesis of cortisone from soybean sterols. Cortisone, often referred to as one of sciences miracle drugs, is effective in the treatment of rheumatoid arthritis (a chronic disease that causes pain, stiffness, and damage to the joints) and other inflammatory diseases and is now widely available. But in the 1940s, the only way to obtain cortisone was to extract it from the bile of slaughtered oxen. To treat a single patient for one year required the bile from nearly 15,000 animals. Because of the limited supply, the cost of the compound was sky-highcertainly out of reach of the majority of patients who needed it most.

Through his experimentation with soybean sterols, Julian came up with a drug he called cortexolone, or Substance S. The only difference between the molecular structure of Substance S and that of cortisone was that Substance S was missing a single oxygen atom. Before long Julian devised a way to add the missing atom to his compound, and by the end of the decade, synthetic cortisone was available to ease the pain of millions of arthritis sufferers. The synthesis of cortisone, and other of Dr. Julians successes, have been widely acclaimed as singular achievements, noted Bims in Ebony. Yet equally important has been his success in making [such] treatments economicalthus available to all. No ivory tower scientist, he has succeeded consistently in working out ways for the efficient production and marketing of his work.

In 1950 Julian was named Chicagoan of the Year for his outstanding contributions to the field of chemistry. Yet, as documented in Black Pioneers of Science and Invention, he continued to be plagued by racial discrimination. Not long after the awards ceremony, he and his wife bought a large home in the exclusive, all-white community of Oak Park, a suburb of Chicago. On Thanksgiving Day even before the Julian family had moved ina band of angry whites attempted to burn the house down. Luckily the disturbance alerted neighbors, who called the fire department in time to save the home. Although the attack was formally denounced by members of the community and by a coalition of Chicago clergymen, less than one year later a dynamite bomb thrown from a car exploded under the bedroom window of the Julian children. The children escaped injury, but their father was incensed. He suffered yet another indignity in the summer of 1951, when, having been invited to participate in a scientific conference at the citys Union League Club, he was informed at the last moment that it was against the rules for people of color to attend.

Julian left the Glidden Company in 1953 to establish his own firm, Julian Laboratories, Inc., in Chicago, and a subsidiary, Laboratorios Julian de Mexico, in Mexico City. Both companies specialized in the production of synthetic cortisone. His research soon revealed that Mexicos wild yams were an even better source for his products than soybeans, and within a few years, Julian Laboratories had become one of the worlds largest producers of pharmaceuticals synthesized from wild yams. After ten years, however, Julian found the pressure of running two large, international businesses overwhelming. In 1964 he sold both of his companies to the Philadelphia pharmaceutical manufacturer Smith, Kline & French for the sum of nearly $2.4 million. He then went on to establish two smaller enterprises in Franklin Park, Illinois: Julian Associates and the Julian Research Institute. There he was able to continue his basic research. He also served as a special consultant to the National Institute of Arthritis and Metabolic Diseases.

During the last ten years of his life, Julian devoted much of his energy to the civil rights movement. The first African American, as well as the first layperson to direct the Council for Social Action of the Congregational Christian Churches, he also served as co-chairman of the National Business and Professional Committee of the NAACPs Legal Defense and Educational Fund. This organization helped to raise money for the legal defense of black people throughout the country. Over the years, Julian received honorary degrees from a dozen universities and served on the boards of numerous professional, scientific, and civic organizations. He also earned a host of prestigious honors, including the 1947 Spingam Award from the NAACP, the Chemical Pioneer Award from the American Institute of Chemists, and the Procter Prize for extraordinary service to science and humanity.

Reluctant to curb his scientific and professional activities even in the face of cancer, Julian continued to work in his laboratory and attend speaking engagements around the country until shortly before his death in 1975. The little remaining energy he had he devoted to his familyand to the care of his 10,000 prize-winning tulips. His spirit lives on in dozens of lifesaving discoveries, as well as in the halls of Percy L. Julian Junior High School in Oak Park, Illinois, which, in 1985, was renamed in honor of the communitys most famous native son. I have had one goal in my life, Julian was quoted as saying in Ebony, that of playing some role in making life a little easier for the persons who come after me. In 1990, following ten years of pressure from minority members of the National Patent Lawyers Association, Percy Lavon Julian was inducted into the National Inventors Hall of Fame, making him one of the first black scientists to be honored in this way.

Books

Davis, Elizabeth L., Fathers of America, Revell, 1958.

Haber, Louis, Black Pioneers of Science and Invention, Harcourt Brace Jovanovich, 1970, pp. 122-45.

Haskins, Jim, Outward Dreams: Black Inventors and Their Inventions, Bantam, 1991.

Wormley, S. L., and Fenderson, L. H., editors, Many Shades of Black, Morrow, 1969.

Periodicals

Ebony, March 1975, pp. 94-96.

Jet, June 3, 1985, p. 23; January 29, 1990, p. 9.

Journal of the American Chemical Society, March 1935, vol. 57, no. 3.

New York Times, April 30, 1968; April 21, 1975, p. 32.

Opportunity, March 1941, vol. 19, no. 3.

Readers Digest, August 1946.

Sun-Times (Chicago), November 23, 1950; July 3, 1951.

Caroline B. D. Smith

Percy Lavon Julian

As the inventor of synthetic cortisone, fire-extinguishing Aero-Foam, and drugs to treat glaucoma, Percy Lavon Julian (1899-1975) made life-enhancing and life-saving products more affordable. Despite facing racial prejudice and segregation at nearly every step of his career, Julian became the first African American to be named director of research at a white-owned firm, and he eventually founded his own Julian Laboratories and Julian Research Institute, where he continued as director until his death.

Percy Lavon Julian was born in Montgomery, Alabama, on April 11, 1899; his father was a railway mail clerk, and his grandfather had been a slave. He credited his strict father with providing the discipline and high standards necessary to his success. Reader's Digest reported that when as a young boy Julian proudly brought home a math test with a grade of 80, his father responded, "A son of mine must not be satisfied with mediocrity. After this make it 100!"

As a teenager, Julian moved with his family to Green-castle, Indiana, home of DePauw University. All six of the Julian children, including Percy, studied there. Although he was required to enter the university as a "sub-freshman, " in 1920 he graduated Phi Beta Kappa, as class valedictorian. He hoped to continue his education and become a research scientist in the field of organic chemistry, but his mentors dissuaded him. Although one of his chemistry professors made inquiries to graduate schools on Julian's behalf, they all replied negatively. "Discourage your bright young colored lad, " one school advised. "We couldn't get him a job when he was done, and it'll only mean frustration. Why don't you find him a teaching job in a Negro college in the South? He doesn't need a Ph.D. for that."

Despite his father's suggestion that he go into medicine, where he could be more independent, Julian persisted in chemistry. He went to Fisk University in Nashville, a school for African Americans, where he taught until 1923. The talent of his students encouraged him to pursue his own dream, and he applied for a research fellowship at Harvard. He earned his Master's degree in a year, finishing in the top group of his class. Had he been white, Harvard would have rewarded him with a post as a teaching assistant, but, as they explained to Julian, they feared that white students from the South would not accept him as a teacher. He stayed at Harvard on minor research fellowships, then returned to the South to teach at all-black schools West Virginia State College and Howard University, where after one year he was appointed head of the chemistry department.

Invented Drug for Glaucoma

Julian's research at Harvard served him well later. He had begun to repeat the experiments of the Austrian chemist Ernst Spth, who had learned to synthesize chemicals such as nicotine and ephedrine-rather than studying these compounds as they appeared in nature, Julian experimented on making these chemicals himself. With the financial backing of a wealthy Harvard classmate, he went to Vienna to study with Spth. Spth welcomed Julian into his household, initiating a father-son relationship and working closely together on synthesizing a variety of naturally occurring chemicals. Through his work with Spth, Julian received his Ph.D. at the University of Vienna in 1931. With his Ph.D., he returned to Howard, and then went again to DePauw, where he both taught and researched, but was denied the title of professor because of his race.

Although he would make one of his most important discoveries at this time, Julian's students remembered him as a committed teacher. Chemist J. Wayne Cole recalled in Ebony magazine, "He was obviously involved in his laboratory work but was essentially an instructor-first and foremost. It was the shaping of the student that appealed to him the most. And believe me, he never tolerated laziness or disinterestedness."

While carrying his teaching load, Julian pursued the problem of synthesizing physostigmine, a chemical known to help in the treatment of glaucoma. Despite years of effort, chemists had not been able to make the chemical in the laboratory. With fundraising help from his former professor Dean William Blanchard, Julian's research progressed rapidly and attracted international attention as he reported his findings in the Journal of the American Chemical Society. When he finally succeeded, he was universally acknowledged as leader in the field of chemistry. Dean Blanchard moved to appoint Julian as the head of DePauw's chemistry department, to make Julian the first professor of chemistry at any traditionally white university in America, and to make DePauw, as Reader's Digest reported, "a chemical Mecca." Blanchard's colleagues refused, calling the appointment "inadvisable."

Soybean Research Enabled More Innovations

With his academic career apparently at a dead-end, Julian received a timely invitation from Chicago's Glidden Company to direct soybean research. While there, he developed a process for isolating and preparing soya protein, which led to a number of important inventions. Among the most highly praised was his "bean soup, " commercially known as Aero-Foam, which the Navy used during wartime to put out fires; he also developed a soy protein for coating paper at a fraction of the cost of the previously used milk casein.

Even more important was his discovery of a technique by which he could mass-produce the hormones testosterone and progesterone. Testosterone was then touted as an anti-aging drug for men, while progesterone helped prevent spontaneous abortion in pregnant mothers. While these hormones were available in nature, they were difficult to get, with the supply limited to the brains and spines of cattle that had been slaughtered. Although German chemists had extracted hormones from soybean oil, the technique they used was expensive and could not provide them in commercial quantities. Julian discovered away to make the oil porous, enabling chemists to create mass quantities of the hormones.

The invention of Compound S, however, is considered Julian's biggest scientific achievement. Natural cortisone was a recognized treatment for rheumatoid arthritis and other illnesses causing muscle pain; to get it, however, the bile from nearly 15, 000 oxen would be required to treat a single patient for a year. The limited supply of cortisone made it impractical as a treatment option. Again using soybean oils, Julian created a drug-Compound S-that could mimic the effects of natural cortisone in the body. His synthesized cortisone resembled natural cortisone in every way, except that it lacked an oxygen atom in a crucial position. Because the body itself could replace that atom when the drug was used, the therapeutic result was the same. Julian's discovery made the benefits of cortisone economically feasible for all patients.

Racial Discrimination Did Not Deter Him

Julian patented these and nearly 130 other chemical innovations, enabling him to earn make a living much larger than that available to most blacks. In 1950, shortly after he had been named "Chicagoan of the Year" in a Chicago Sun-Times poll, Julian moved into the white, middle-class suburb of Oak Park, Illinois. He purchased an ornate, 15-room house and planned extensive landscaping and improvements, but even before he and his family moved in, they received threats and were the victims of an attempted arson. The water commissioner refused to turn on their water, until the family threatened to go to court. Julian was compelled to hire a private guard to patrol the property 24 hours a day. He told Time, "We've lived through these things all our lives. As far as the hurt to the spirit goes, we've become accustomed to that."

Julian continued to confront racism in his professional life as well. In 1951, when the Research Corporation of New York City invited Julian, along with 34 other scientists, to hear a talk at the Union League Club of Chicago, the club's manager contacted the organization and informed them that Julian would not be permitted to enter the building. The New York Times reported that the club's directors had issued "explicit instructions" forbidding Julian's attendance. By 1956, he had become more actively involved in opposing racial injustice. He became the first black man to chair the General Council of Congregational Christian Churches' Council for Social Action. The council voted to raise litigation funds for a delegate who had been refused admission to an American Legion Post, and, according to the New York Times, called on members to "support nonsegregated practices in selling, buying, and leasing property."

In 1967, Julian and North Carolina Mutual Life Insurance Company president Asa Spaulding organized a group of 47 wealthy business persons and professionals to raise money for the NAACP Legal Defense and Educational Fund. The group, calling itself the National Negro Business and Professional Committee for the Legal Defense Fund, announced in the New York Times, "This means the Negro millionaire is coming of age and taking a responsible place in the community." The committee planned to raise $1 million a year for cases involving voting rights, school desegregation, and job discrimination. Julian had been connected with the NAACP since 1947, when he won their Spingarn Medal Award.

Founded His Own Laboratories

Julian's financial success also enabled him to leave Glidden in 1953 and found Julian Laboratories. In addition to his suburban Chicago laboratory, he established subsidiaries in Mexico and Guatemala, which studied the possible medical benefits of the Mexican yam. These pharmaceutical businesses were so successful that eventually Julian, approaching his mid-60s, found the pressure to be too much, and in 1961 he sold them for nearly $2.4 million. In 1964, he retired as president from Julian Laboratories, then became director of Julian Research Institute and president of Julian Associates.

In 1974, Julian became increasingly ill, and was diagnosed with cancer of the liver. Despite a lack of energy and a difficult schedule of treatment, Julian continued to work and give speeches. In November of that year, he was honored by Sigma Xi, a society of research scientists, with the Procter Prize for extraordinary service to science and humanity. As Ebony reported, in his acceptance speech he discussed the benefits and drawbacks of scientific advancements: "Many of these successes have been abused, he acknowledged, while others have been the subjects of material applications having little implication for the enrichment of the spirit; man has treasured them as weapons or employed them as gadgets." Despite this, he said, he "shares the humanistic faith in an ordered, purposeful and meaningful reality."

Shortly before his death, Julian announced that he was satisfied with his life's work. "I have had one goal in my life, " he said, "that of playing some role in making life a little easier for the persons who come after me." He died in April of 1975. In addition to many academic honors and citations he received during his lifetime, he was honored in 1993 by the U.S. Postal Service with a postage stamp in the Black Heritage Series. He was also honored by the city of Oak Park, Illinois, which named a middle school after one of its first residents.

Further Reading

Contemporary Black Biography, vol. 6, Gale, 1994.

Ebony, March 1975.

Jet, June 3, 1985; January 29, 1990.

New York Times, January 18, 1950; July 19, 1951; June 28, 1956; March 20, 1967; April 21, 1975.

Reader's Digest, August, 1946.

Stamps, February 13, 1993.

Time, December 4, 1950.

"Percy Julian School, " http://kato.TheRamp.net/julian/bio.html (March 20, 1998).

Julian, Percy Lavon

( b. Montgomery, Alabama, 11 April 1899; d. Waukegan, Illinois, 19 April 1975)

organic chemistry.

Percy Lavon Julian was the oldest of the six children ofJames Sumner and Elizabeth Lena (Adams) Julian. His mother was a school teacher, and his father, originally a teacher, took a job as a railway mail clerk shortly after Percy was born. Although public education for Alabama blacks at the time rarely extended beyond eighth grade, in 1916 Julian graduated from the State Normal School for Negroes in Montgomery, which his parents had attended, and he entered DePauw University in Greencastle, Indiana. When he received his A.B. degree in 1920. Julian was elected to Phi Beta Kappa and named valedictorian of his class. For two years he served as an instructor in chemistry at Fisk University, then began graduate study at Harvard University, where he received his A.M. degree in chemistry in 1923. He remained at Harvard as a research fellow until 1926. He then served as professor of chemistry, for one year at West Virginia State College for Negroes and for two years at Howard University.

In 1929 Julian received a fellowship from the Rockefeller Foundation to continue his graduate work at the University of Vienna. His research there under the direction of Ernst Späth on the alkaloids of Corydalis cava earned him the Ph.D. degree in 1931. He returned to Howard University as head of the chemistry department for one year, then was a research fellow and taught organic chemistry at DePauw University from 1932 to 1936. On 24 December 1935 Percy Julian married Anna Johnson, a sociologist. They had two children, Percy Lavon, Jr., and Faith Roselle.

When he was denied a professorship at DePauw because of prejudice against blacks, Julian became director of research of the Soya Products Division of the Glidden Company, Chicago, Illinois. Later he also was named director of research for Glidden's Durkee Famous Foods Division and manager of the Fine Chemicals Division. In 1954 Julian started his own chemical firm, Julian Laboratories, which manufactured intermediates for industrial production of steroids. After selling his company in 1961 he continued as president for several years. In 1964 he founded the Julian Research Institute, where he served as director until his death from cancer at age seventy-six.

Julian's financial success and fame enabled him to be a major force in the civil rights movement. In 1967 he was appointed cochairman of a group of successful black Americans who raised money for the Legal Defense and Education Fund of the National Association for the Advancement of Colored People. This fund enabled lawsuits to be brought to enforce civil rights laws. He was active in civic affairs and many national organizations and was elected a member of the National Academy of Sciences in 1973.

Percy Julian's significant research in the chemistry of natural products began with the total synthesis of physostigmine, an alkaloid isolated from Calabar beans and important in the treatment of glaucoma. This he accomplished in 1935 with the assistance of Josef Pikl, formerly a fellow student at the University of Vienna whom Julian had assisted in coming to the United States to work with him. Their total synthesis confirmed the structural formula assigned to physostigmine. Julian also at this time extracted from Calabar beans stigmasterol, a phytosterol that reportedly could serve as raw material for synthesis of male and female hormones.

Julian's principal work during his eighteen years directing research at the Glidden Company was the development of processes for preparation of substances of commercial value from soybeans. When he arrived in 1936, the firm had purchased a new plant in Germany for the extraction of oil from soybeans for the production of refined oils for paints and other uses; he supervised the assembly of this plant at Glidden. Julian's first laboratory task was to develop processes for further separation and purification of the various components of the extracted, oil-free soybean meal and to determine uses for them. Julian's laboratory prepared refined protein products that could replace milk casein in industrial applications, such as coating and sizing of paper and in manufacture of paints and other Glidden products. Julian designed and supervised the construction of a plant to produce these soya proteins; its eventual daily output of forty tons of commercially important products made the Soya Products Division one of Glidden's most profitable divisions. Soy protein was also developed as the base of an oxygenimpenetrable, fire-fighting foam used by the U.S. armed forces in World War II. Theremaining meal, following the separation of these protein products, was shown to be of value as a supplement in livestock and poultry feeds. Julian and his laboratory workers also developed derivatives of the crude oil fraction. including edible oils for preparation of margarine, saladoils, and dressings, and soylecithin, used widely as an emulsifier in manufacture of foods. As the scope of research expanded. Julian hired additional chemists, some of whom were his former students at DePauw University, and within ten years his research program developed into an important industrial laboratory.

A change in the direction of Julian's research occurred in 1940 when he began recovering sterols from soybean oil. At that time clinicians were discovering many uses for the newly discovered sex hormones. However, only minute quantities of progesterone, testosterone, and the estrogens could be produced from the extraction of hundreds of pounds of spinal cords, testicles, or ovaries. Soybean oil was known to contain a mixture of sterols, and Julian perfected means by which soya sterols could be isolated and converted to these hormones. At one stage in processing the oil a porous, solid. foamliike soap could be produced, from which the soya sterols were extracted with solvents. Glidden manufactured large quantities of progesterone and testosterone, utilizing on an industrial scale the chemical reactions for the modification of sterols devised in Julian's laboratory, which now included over fifty chemists. Julian and his co-workers published many articles on the chemistry of sterols in the Journal of the American Chemical Society, and they obtained patents on key processes in preparation of steroids from soybeans.

In 1949 the importance of cortisone for treatment of rheumatoid arthritis produced a rush by many pharmaceutical firms to produce cortisone and its analogs, yet most of the syntheses were dependent upon scarce bile acid starting materials. Julian undertook the synthesis of cortisone from pregnenolone, available in abundance from soya sterol, and devised a multistep process for conversion of pregnenolone to cortexolone (Reichstein's Substance S). with differs from cortisone in lacking an oxygen at the C-11 position. The industrial production of cortisone was revolutionized in 1952 when the Upjohn Company announced that oxygenation at C-11 could be accomplished in high yield by microbiological oxidation. This made progesterone, pregnenolone, and cortexolone valuable intermediates for the production of a variety of corticoid drugs, and Upjohn sought manufacturers capable of supplying the ton quantities needed.

It was at this time that Percy Julian left his position at Glidden to start Julian realized that an even more abundant plant source of hormones was a Mexican Diosorea, commonly called wild yam, rich in diosgenin. In a subsidiary in Mexico City, Laboratorios Julián de México, 16-dehydropregnenolone oxide was prepared from diosgenin and shipped to Julian Laboratories in the United States. There Julian and his team of chemists transformed "oxide" into many derivatives of cortexolone through a complex series of reactions they devised. These valuable intermediates were sold to pharmaceutical firms for production via microbiological oxidation of a wide variety of steroids of the cortisone family. In 1961 Julian sold his firm to Smith, Kline, and French Laboratories for 2.3 million dollars. In later years he continued his research on steroid chemistry as director of the Julian Research Institute. Percy Julian's skill in guiding industrial research and his creativity in novel chemical syntheses are well illustrated in his publications and patents dealing with chemical manipulations of the structures of steroids.

BIBLIOGRAPHY

1. Orginal Works. A list of Julian's scientific publications and patents is in Bernhard Witkop. " Percy Lavon Julian, 1899-1975," in Biographical Memoirs. National Academy of Sciences. 52 (1980). 223-266. His most important articles include "Studies in the Indole Series. V. The Complete Synthesis of physostigmine (Eserine)," in Journal of the American Chemical Society. 57 (1935), 755-757, written with Josef Pikl; "Sterols. IX. Theselective Halogenation and Dehalogenation of Certain Steroids (Part I)" ibid., 72 (1950), 365-366, writen with willian J Karpel; "sterols. XIII. Chemistry of the Adrenal cortex Steroids." in Recent Progress in Hormone Research. 6 (1951).195-214: "Sterols. XV. Cortisone and Analogs. Part I 16a-Hydroxy and 16a, 17a-Epoxy Analogs to Cortisone," in Journal of the American Chemical Society. 77 (1955). 4601-4604. written with Wayne Cole. Edwin W. Meyer. and Bernard M. Regan: and "Sterols XVI. Cortisone and Analogs. Part 2, 17a21-Dihydroxy4-pregnene-3.12.20-trione." ibid., 78 (1956) 3153-3158, written with Chappelle C.Cochrane. Arthur Magnini, and William J. Karpel.

Addresses and written works for general audiences include "The Chemist as Scholar and Humanist," in Chemist (American Institute of Chemists). 42 (1965).101-104; "On Being Scientist. Humanist. and Negro, ' in Stanton L. Wormley and Lewis H. Fenderson, eds., Many Shades of Black ( New York, 1969), 147-157;and "Science, an Ally of the Humanities." in American Scientist, 63 (1975).13-15.

Some personal papers are in the possession of Dr. Anna J. Julian.

II. Secondary Literature. W. Montague Cobb, "Percy Lavon Julian," in Journal of the National Medical Association. 63 (1971), 143-150, and "Onward and Upward-Percy Lavon Julian, 1899-1975." in Crisis, 85 (1978).166-171: Louis Haber. Black Pioneers of Science and Invention ( New York.1970), 86-101;and Max Tishler, "Percy L.Julian, the Scientist." in Chemist (American Institute of Chemists). 42 (1965). 105-113. The text of the addresses given at a symposium to honor Julian on 12-13 May 1972 at MacMurray College is in the library of that college in Jacksonville, lllinois.

Daniel P. Jones

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A steroid chemist and an entrepreneur, Percy Julian ingeniously figured out how to synthesize important medicinal compounds from abundant plant sources, making them more affordable to mass-produce.

In the 1930s chemists recognized the structural similarity of a large group of natural substances-the steroids. These include the sex hormones and the cortical hormones of the adrenal glands. The medicinal potential of these compounds was clear, but extracting sufficient quantities of them from animal tissue and fluids was prohibitively expensive. As with other scarce or difficult-to-isolate natural products, chemists were called upon to mimic nature by creating these steroids in the lab and later by modifying them to make them safer and more effective as drugs. Chemists found their starting materials in certain plant substances that were also steroids. Percy Lavon Julian (1899-1975) was among the many scientists, including Russell Earl Marker, Carl Djerassi, and George Rosenkranz, who participated actively in the synthesis and large-scale production of steroids from plant compounds.

Education and Early Career

Julian was born in Montgomery, Alabama, the son of a railway mail clerk and the grandson of enslaved people. In an era when African Americans faced prejudice in virtually all aspects of life, not least in the scientific world, he succeeded against the odds. Inadequately prepared by his high school, he was accepted at DePauw University in Greencastle, Indiana, as a sub-freshman, meaning that he had to take high-school courses concurrently with his freshman courses. Majoring in chemistry, he graduated as valedictorian of his class in 1920. After graduation he taught chemistry at Fisk University for two years before winning an Austin Fellowship to Harvard University, where he completed a master's degree in organic chemistry. After Harvard he returned to teaching at West Virginia State College and Howard University.

Physostigmine for Glaucoma

In 1929 Julian traveled to the University of Vienna, Austria, to begin doctoral studies on the chemistry of medicinal plants. Two years later, with degree in hand, he and a Viennese colleague, Josef Pikl, took positions back in the United States at Howard and two years later moved to DePauw. There they accomplished the first total synthesis of physostigmine, the active principle of the Calabar bean, used since the end of the 19th century to treat glaucoma. Physostigmine, an alkaloid, eases the constriction of outflow channels from the eye's aqueous humor to relieve high pressure there, which, if left untreated, damages the retina and eventually causes blindness.

Steroids from Soybeans: Progesterone

Meanwhile researchers in many countries were seeking innovative and cost-effective ways to synthesize steroids, including cortisone and the sex hormones. German chemists discovered that the steroid stigmasterol, which Julian had obtained as a by-product of the physostigmine synthesis but was also obtainable from soybeans, could be used in the synthesis of certain sex hormones, including progesterone, a female sex hormone that was important in helping pregnant women avoid miscarriages. In pursuit of this lead, in 1936 Julian wrote to the Glidden Company in Chicago, requesting samples of their soybean oil. Through a series of events he wound up being hired by Glidden instead, as their director of research in the Soya Division, where he set about figuring out ways to make new products from soybeans.

Three years after arriving at Glidden, Julian learned from plant workers that water had leaked into a tank of purified soybean oil and formed a solid white mass. Immediately identifying the substance as stigmasterol, he realized he had stumbled upon a method for producing large amounts of the steroid from soybeans. Though scientists already knew how to synthesize progesterone from stigmasterol, they didn't have a method for doing it on a massive scale. Now with large quantities of stigmasterol at hand, he was able to develop an innovative industrial process for converting it to progesterone in bulk, producing five to six pounds of progesterone per day (worth thousands of dollars in those days). Soon other sex hormones were in production.

Cortisone and Hydrocortisone

In 1948 scientists at the Mayo Clinic announced their landmark discovery of cortisone, which had remarkable effects on rheumatoid arthritis, and Julian jumped into the exciting competition to synthesize cortisone inexpensively (see also Carl Djerassi). Cortisone is a cortical hormone of the adrenal gland. In 1949 Julian developed a new synthesis for a related substance (called "Substance S") also present in the adrenal cortex and differing from cortisone by only an oxygen atom. From this substance he was able to synthesize both cortisone and hydrocortisone. Hydrocortisone and its derivatives today are more widely prescribed than cortisone products, and most industrial syntheses still begin along the same route that Julian pioneered.

Later Life

Julian remained at Glidden until 1954, when he founded his own company, Julian Laboratories of Franklin Park, Illinois, and Mexico City (which he eventually sold to Smith, Kline and French). Throughout his life he was socially active in groups seeking to advance conditions for African Americans, helping to found the Legal Defense and Educational Fund of Chicago and serving on the boards of several other organizations and universities.
The information contained in this biography was last updated on October 15, 2020.

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Commercialization of Taxol®

In August 1978 Monroe Wall received a letter from John Douros, who had replaced Jonathan Hartwell at the CCNSC, that read: "Dear Monroe: Can you help this poor girl?" Attached was a letter from Susan Horwitz asking for some radiolabeled Taxol ® to conduct experiments on its mechanism of action. Like many researchers, Horwitz, a molecular pharmacologist in the Albert Einstein College of Medicine at New York's Yeshiva University, had been hearing reports about Taxol ®. She had managed to obtain a few milligrams of the substance, which she used to kill cancer cells growing in a culture. Determined to find out how it worked, Horwitz pressured NCI to get her more Taxol ®.

Supply remained a problem. In July 1977 Matthew Suffness of the NCI placed an order with the USDA for 7,000 pounds of bark, which meant killing about 1,500 trees. Such a large order attracted the attention of environmentalists who began to wonder about the government's sudden interest in the Pacific yew, long considered a "trash tree." To environmentalists the tree, scattered in patches hidden within millions of acres, had a place in the virginal, old-growth forests of the Pacific Northwest. Environmentalists feared a massive attack on the Pacific yew would spell ecological disaster for the region. In the next decade this fear became enmeshed in the debate over the northern spotted owl, which lived in the forests of the Pacific Northwest and which the federal government eventually declared threatened.

Horwitz was able to get enough Taxol ® to run tests that revealed its lethal secret, which turned out to be a mechanism completely new to scientists. Previous compounds killed cancer cells by inhibiting their division; they did this by preventing the production of ultra-fine filaments called microtubules that enable cells to divide. Cells manufacture millions of microtubules and use them as building blocks for a new cell. When a new cell breaks off, the microtubules become fragments of the protein tubulin. Before Taxol ® anticancer agents worked by inhibiting the polymerization of tubulin to form microtubules; hence, the cells could not divide.

Horwitz discovered that Taxol ® worked differently. Instead of preventing the formation of microtubules, it stimulated their development. Cells treated with Taxol ® begin churning out so many microtubules that they are unable to coordinate cell division. As a result, cells die of continued attempts to replicate their DNA in the absence of the ability to divide.

Armed with this information, Suffness at NCI was able to argue that, because of its unique structure and mechanism of action, Taxol ® was a candidate for further development. Buttressing that argument was Taxol's ® success in causing regression in the mammary tumor xenograft. Suddenly, Taxol ® was "hot," with some seeing it as a potential "miracle drug."

Then came a disastrous discovery: Taxol ® is virtually insoluble in water. No matter how good Taxol ® was shown to be, if it could not be added to a medium so that it could be administered intravenously, it was worthless. Without any way of getting Taxol ® into a patient, clinical trials could not begin. But after a year of looking, the NCI drug formulation team found that Taxol ® dissolved in a special elixir made of castor oil and marketed as Cremophor EL. This paved the way for Taxol ® to move into clinical trials on humans.

Taxol ® progressed fairly smoothly through clinical Phase I and Phase II trials, once patients were premedicated to suppress severe allergic reactions to Cremophor EL. In fact, the results of Phase II trials against refractory ovarian cancer showed a previously unheard of response rate of thirty percent. The clamor about Taxol ® intensified, forcing NCI to do the math. If Taxol ® were made available to all victims of ovarian cancer, the institute would have to produce 240 pounds of the drug. That would mean killing 360,000 Pacific yews. It did not take a mathematical prodigy to understand that this was an equation without a future.

The numbers encouraged scientists to search for a synthesis, to in effect short cut nature. The first success story came in France, where Pierre Potier looked at a semi-synthesis. From the needles of the ubiquitous Taxus baccata, or English yew, Potier extracted 10-deacetylbaccatin III, commonly known as 10-DAB. The English yew is loaded with this compound, which contains the complex core of Taxol ® minus the relatively simple side chain. Most importantly, 10-DAB comes from the needles, a renewable resource. After several years of trying, Potier and his colleagues succeeded in marrying 10-DAB to a synthetic version of the tail to achieve a semi-synthesis of Taxol ®. This accomplishment led to the development of a plethora of semi-synthetic versions of Taxol ®. Eventually, Robert Holton and colleagues at Florida State University developed a commercially viable semi-synthetic procedure.

With the clinical trials going well the NCI began to look for a pharmaceutical company willing to take a chance on turning Taxol ® into a marketable drug. In August 1989 the institute advertised that it had a cooperative research and development agreement to issue to the company with the best proposal. Later in the year, the grant went to Bristol-Myers, soon to merge with Squibb, another giant in the field. Bristol-Myers Squibb worked out a deal with Holton under which it agreed to use his semi-synthetic process for the production of Taxol ®.

In December 1992, thirty years after USDA botanists first sampled Taxus brevifolia in a Washington State forest, and more than twenty years after Wall and Wani reported the isolation and structure of Taxol ®, the Food and Drug Administration granted approval for Taxol's ® use against refractory ovarian cancer. It has since been approved for use in the treatment of breast cancer and AIDS-related Kaposi's sarcoma.

In the mid-1990s Monroe Wall and Mansukh Wani wrote of their delight "that their initial discovery... of a novel natural product with excellent activity in a number of animal models has presently reached the stage where taxol is now available in adequate quantity for therapeutic use. Undoubtedly, there are other highly active natural products from plant, marine, and fungal sources as yet unknown which, when discovered, will have therapeutic value. Cancer is not one, but several hundred diseases and will require many different types of agents." ¹⁰

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Discovery of Camptothecin and Taxol - National Historic Chemical Landmark - American Chemical Society

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In August 1978 Monroe Wall received a letter from John Douros, who had replaced Jonathan Hartwell at the CCNSC, that read: "Dear Monroe: Can you help this poor girl?" Attached was a letter from Susan Horwitz asking for some radiolabeled Taxol ® to conduct experiments on its mechanism of action.

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A computer-
generated model of a Taxol molecule. Courtesy of NCI. 1991.

Paclitaxel, the most well-known natural-source cancer drug in the United States, is derived from the bark of the Pacific yew tree ( Taxus brevifolia) and is used in the treatment of breast, lung, and ovarian cancer, as well as Kaposi's sarcoma.

1962 Samples of the Pacific yew's bark were first collected in 1962 by researchers from the U.S. Department of Agriculture (USDA) who were under contract to NCI to find natural products that might cure cancer. Two years later, Dr. Monroe E. Wall, Dr. Mansukh Wani, and colleagues at the Research Triangle Institute's Natural Product Laboratory in Research Triangle Park, NC, discovered that extracts from this bark contained cytotoxic activity. In 1965, additional samples of bark were collected and sent to Dr. Wall's group for identification and purification of the extract's most active component. It took the researchers at the Research Triangle Institute several years to isolate paclitaxel in its pure form, but once they did, NCI assigned the compound an NSC number and testing began to identify paclitaxel's biological action.

1977 It was not until 1977, when NCI was able to confirm antitumor activity in the mouse melanoma B16 model, that paclitaxel, also known by its trade name, Taxol, was selected as a candidate for clinical development. Activity was also observed in animal models against MX-1 mammary, LX-1 lung, and CX-1 colon tumors.

Also during that year, Dr. Susan Horwitz, Albert Einstein College of Medicine of Yeshiva University, was given a grant by NCI to study Taxol's mechanism of action. Dr. Horwitz proved to be a good candidate to study Taxol, in part because of her interest in naturally occurring small molecules and their use in treating cancer. ¹

Dr. Horwitz found that Taxol was able to bind to a cell's microtubule assembly and slow cell division and growth by stabilizing the microtubules, preventing shrinkage and therefore blocking the segregation of the chromosomes. ²

Because of difficulties harvesting Taxol and because of the complexities involved in synthesizing the compound, development toward the clinic was slow. The drug, however, showed effectiveness against mammary tumors and ovarian cancer, pushing researchers to find a means of isolating large quantities for clinical use. The first company to achieve large-scale production of Taxol was Polysciences, Inc. Clinical trials became possible when a method was derived to extract a precursor of Taxol, 10-deacetyl-baccatin III, from the common yew Taxus baccata (which many people have in their gardens). The precursor was then converted by chemical synthesis to Taxol. Currently, a cell culture method developed by Phyton Catalytic is used by Bristol-Myers Squibb (BMS) to produce the drug. ³

Taxol posed other challenges, too. It was difficult to formulate into a delivery system acceptable for human use. Initial activity was observed with bulk drug suspended in solution. Although Taxol was soluble in 75% polyethylene glycol, repeated testing using this formula against both B16 and P388 tumors produced inferior results. When the drug was formulated in an ethanol, cremophor, and saline solution (ratio 5:5:90) to a concentration of 0.3 to 0.6 mg/mL, the intraperitoneal activity was preserved at the initial levels. Preclinical toxic effects were most evident in tissues with a high cell turnover, such as hematopoietic, lymphatic, gastrointestinal, and reproductive tissues.

1984 In 1984, NCI began phase I clinical trials of Taxol against a number of cancer types. Demand for Taxol spiked in 1989 after investigators at Johns Hopkins reported that the drug produced partial or complete responses in 30% of patients with advanced ovarian cancer. ⁴

1992–present In December 1992, the FDA approved Taxol for the treatment for ovarian cancer. Researchers also tested the effectiveness of Taxol as a treatment for advanced breast cancer. Subsequent clinical trials found that the drug was effective against this disease, and, in 1994, the FDA approved Taxol for use against breast cancer. ⁴

Clinical trials to test Taxol against other types of cancer and in combination with other therapies are currently in progress.

To date, Taxol is the best-selling cancer drug ever manufactured. Annual sales of the drug peaked in 2000, reaching $1.6 billion. ⁵

Taxol
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"The chemical structure of Taxol is unique and it looked extremely interesting to me, so I said yes, please send me 10 milligrams. Within a month we knew that we had a very interesting molecule that was doing something to cells, which no one else had seen occur with a small molecule. It was very exciting."

—Susan Horwitz, Ph.D. ¹

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A computer- generated model of a Taxol molecule. Courtesy of NCI. 1991. Paclitaxel, the most well-known natural-source cancer drug in the United States, is derived from the bark of the Pacific yew tree ( Taxus brevifolia) and is used in the treatment of breast, lung, and ovarian cancer, as well as Kaposi's sarcoma.

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A Story of Discovery: Natural Compound Helps Treat Breast and Ovarian Cancers - National Cancer Institute

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A Story of Discovery: Natural Compound Helps Treat Breast and Ovarian Cancers - National Cancer Institute

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Pathway to Discovery

In the second half of the 20th century, researchers realized the need for systemic treatments, such as chemotherapy and hormone therapy, to destroy cancer cells that had spread from the site of the original tumor to other parts of the body. They searched far and wide for the most effective products to cure cancer. In the 1960s, NCI-funded researchers discovered the lifesaving natural compound paclitaxel, which later became the cancer drug Taxol. Since its discovery, this remarkable compound has expanded treatment options for patients with breast and ovarian cancers, giving them hope for a cure. Taxol is also used to treat non-small cell lung cancer, pancreatic cancer, and AIDS-related Kaposi sarcoma. Today, it is recognized on the World Health Organization's Model List of Essential Medicines, a list of the necessary and most important medications needed to support a basic health care system.

This extraordinary story of discovery begins in 1955, when NCI created the Cancer Chemotherapy National Service Center (CCNSC) in response to a call for increased cancer screening and treatment programs. At its inception, CCNSC mostly analyzed known and synthetic compounds. By 1960, NCI expanded the center through a partnership with the U.S. Department of Agriculture (USDA) to search for possible cancer cures from natural plant and animal products. Between 1960 and 1981, researchers collected and tested an incredible 30,000 samples under this program.

One of these samples proved to be pivotal to cancer therapy. In 1962, on an excursion in Washington State, USDA botanist Arthur Barclay collected bark and other samples from the Pacific yew tree. Two years later, Monroe E. Wall, Ph.D., and Mansukh Wani, Ph.D., who were under contract to NCI at the Research Triangle Institute in North Carolina, discovered that extracts from the Pacific yew were toxic to living cells. Dr. Wall and his colleagues then isolated the most cytotoxic compound from the bark of the tree and called it paclitaxel.

In 1977, after showing efficacy in mouse models, NCI confirmed paclitaxel's antitumor activity and the drug was selected as a candidate for clinical development. In 1979, through a grant from NCI, Dr. Susan Band Horwitz at the Albert Einstein College of Medicine of Yeshiva University discovered how paclitaxel works. Dr. Horwitz found that the compound is an antimitotic agent that blocks cancer cell growth by stopping cell division, resulting in cell death. Even more exciting was that paclitaxel worked to prevent cell division through a different mechanism compared with other antimitotic drugs available at the time. This was an extraordinary discovery, as clinicians were struggling to treat patients who were developing drug resistance or not responding to available treatment options. Paclitaxel was proving to be a very promising discovery in cancer treatment.

The chemical structure of Taxol is unique and it looked extremely interesting to me.... Within a month, we knew that we had a very interesting molecule that was doing something to cells, which no one else had seen occur with a small molecule. It was very exciting.

Susan Band Horwitz, Ph.D., Distinguished Professor, Department of Molecular Pharmacology at Albert Einstein College of Medicine

Enhancing Cancer Care

In 1987, NCI-funded researcher Ross C. Donehower, M.D., and colleagues at the Johns Hopkins Oncology Center described paclitaxel as "a unique plant-derived substance that stops tumor growth." These researchers also observed a dramatic and prolonged response to paclitaxel in a patient with cisplatin-resistant ovarian cancer during a phase I clinical trial. These initial results gave doctors hope that they might have a new tool to treat ovarian cancer that was not responding to traditional approaches.

Despite encouraging findings, subsequent clinical trials were delayed because of how slowly Pacific yew trees grow and the large amount of bark needed to produce therapeutic doses of the active ingredient, paclitaxel. There were also complexities involved in developing a synthetic version of the compound. Despite these challenges, in 1989-10 years after Dr. Horwitz's research-the results were published from a phase II clinical trial led by NCI-funded researcher William P. McGuire, M.D., at the Johns Hopkins Oncology Center. Dr. McGuire and his colleagues found that an impressive 30 percent of patients with advanced ovarian cancer responded positively to paclitaxel treatment.

The slow growing nature of the Pacific yew and increasing demand for the compound led to another roadblock. Despite successful clinical trials, the drug was very expensive to manufacture and the ecological cost was too high-harvesting the bark kills the tree. To meet these challenges, researchers around the world raced to develop a synthetic form of the compound. In 1991, NCI partnered with the pharmaceutical company Bristol-Myers Squibb (BMS) for the commercial production of Taxol, using a semisynthetic form of the compound. A year later, the Food and Drug Administration approved Taxol for the treatment of ovarian cancer and in 1994 for the treatment of breast cancer. Today, Taxol remains one of the best plant-based cancer treatments available.

What's Next for Taxol Research?

The future is bright for Taxol research. Currently, researchers are exploring ways to expand and improve the drug's use in cancer treatment. NCI is supporting several clinical trials to assess Taxol's effect on ovarian, peritoneal, and fallopian tube cancers at different stages. Also, Dr. Horwitz and her team are continuing to conduct NCI-funded research on how tumor cells resist Taxol at the molecular level by studying Taxol's interactions with other drugs to overcome drug resistance in tissue culture.

Researchers are also investigating the effect of Taxol on other types of tumors, such as head and neck, prostate, bladder, cervical, esophageal, thyroid and uterine cancers. Recent research is examining exactly how Taxol works to disrupt the normal function of microtubules, part of the cell's key internal structure involved in mitosis. This work will help to develop better cancer drugs and improve Taxol and other drugs that kill cancer cells by inactivating the microtubules.

Taxol's success has led other organizations and companies to join efforts to expand Taxol research. When combined with other cancer drugs, Taxol holds great promise to deliver more lifesaving treatment options. The Metastatic Pancreatic Adenocarcinoma Clinical Trial (MPACT) examined combination therapy in patients with metastatic pancreatic cancer. They found that patients treated with nab-paclitaxel (a form of paclitaxel) in combination with gemcitabine lived longer than patients treated with gemcitabine alone. Patients treated with both cancer drugs also lived longer without their disease getting worse ( progression-free survival). In 2013, based on the results from MPACT, the FDA approved nab-paclitaxel for use in combination with gemcitabine to treat patients with metastatic pancreatic cancer.

Research to Practice: NCI's Role

As a leader in cancer control and prevention, NCI championed research that led to the discovery and development of Taxol, a lifesaving cancer drug. NCI's Developmental Therapeutics Program (DTP) supported the essential preclinical work and secured the difficult to get raw material needed to isolate the pure compound. Upon identification of Taxol, DTP developed a suitable formulation for human use, which was manufactured under NCI contracts, and supplied Taxol for the phase I and early phase II clinical trials. For more than four decades, NCI expanded Taxol research to provide improved treatment options for patients with breast and ovarian cancers. Thanks to NCI's ongoing investment, Taxol offers better treatment outcomes, increased life expectancy, and improved quality of life for cancer patients. Today, NCI continues to support basic research that explores how Taxol works in different cell types and how it can be used to treat other types of cancer.

Key Takeaway

NCI researchers deliver a breakthrough discovery with Taxol, a naturally derived compound that expands treatment options for patients with breast and ovarian cancers.

Selected Resources

Albrethsen J, Angeletti RH, Horwitz SB, Yang CP. Proteomics of cancer cell lines resistant to microtubule-stabilizing agents. Mol Cancer Ther. 2014;13(1):260-269. [ PubMed Abstract].

American Chemical Society. National Historic Chemical Landmarks. Discovery of Camptothecin and Taxol®. http://www.acs.org/content/acs/en/education/whatischemistry/landmarks/camptothecintaxol.html. Published 2003. Accessed November 24, 2014.

Chesnoff S. The use of Taxol as a trademark. Nature. 1995;373(6513):370. [ PubMed Abstract]

Donehower RC, Rowinsky EK, Grochow LB, et al. Phase I trial of Taxol in patients with advanced cancer. Cancer Treat Rep. 1987;71(12):1171-1177. [ PubMed Abstract]

Herman LC, Chen L, Garnett A, et al. Comparison of carboplatin-paclitaxel to docetaxel-cisplatin-5-flurouracil induction chemotherapy followed by concurrent chemoradiation for locally advanced head and neck cancer. Oral Oncol. 2014;50(1):52-58. [ PubMed Abstract]

McGuire WP, Rowinsky EK, Rosenshein NB, et al. Taxol: a unique antineoplastic agent with significant activity in advanced ovarian epithelial neoplasms. Ann Intern Med. 1989;111(4):273-279. [ PubMed Abstract]

Printz C. Scientist honored for work with paclitaxel: interest in a unique chemical structure leads to drug that helps millions. Cancer. 2011;117(3):2827-2828. [ PubMed Abstract]

Sanders R. Discovery of how Taxol works could lead to better anticancer drugs. UC Berkeley News Center. 2014, May 22. http://newscenter.berkeley.edu/2014/05/22/discovery-of-how-taxol-works-could-lead-to-better-anticancer-drugs/

Schiff PB, Horwitz SB. Taxol stabilizes microtubules in mouse fibroblast cells. Proc Natl Acad Sci. 1980;77(3):1561-1565. [ PubMed Central]

Von Hoff DD, Ervin T, Arena FP, et al. Increased survival in pancreatic cancer with nab-paclitaxel plus gemcitabine. N Engl J Med. 2013;369(18):1691-1703. [ PubMed Central]

Weaver BA. How Taxol/paclitaxel kills cancer cells. Mol Bio Cell. 2014;25(18):2677-2681. [ PubMed Central]

World Health Organization. WHO Model List of Essential Medicines. 18th edition. http://apps.who.int/iris/bitstream/10665/93142/1/EML_18_eng.pdf?ua=1. Published 2013. Accessed November 24, 2014.

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In the second half of the 20th century, researchers realized the need for systemic treatments, such as chemotherapy and hormone therapy, to destroy cancer cells that had spread from the site of the original tumor to other parts of the body. They searched far and wide for the most effective products to cure cancer.

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Synthetic Fuels Could Eliminate Entire U.S. Need for Crude Oil, Create 'New Economy" - Princeton University 

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Synthetic Fuels Could Eliminate Entire U.S. Need for Crude Oil, Create 'New Economy" - Princeton University 

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Synthetic fuels could eliminate entire U.S. need for crude oil, create 'new economy'

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The United States could eliminate the need for crude oil by using a combination of coal, natural gas and non-food crops to make synthetic fuel, a team of Princeton researchers led by chemical and biological engineering professor Christodoulos Floudas has found.

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With oil and fossil fuel resources dwindling around the world, the race to find the next big energy solution is definitely on. There may not be a magic bullet to solve that energy crisis, or a perfect fuel that is infinitely available and doesn't pollute the environment. But one option, synthetic fuels -- or synfuels -- offers some advantages and some drawbacks when compared to conventional oil-based fossil fuels. Synthetic fuel is a category of fuels that includes any fuel "produced from coal, natural gas or biomass feedstocks through chemical conversion" [source: U.S. Energy Information Administration]. These types of fuels are often called Fischer-Tropsch liquids, after the process used to create them. The synfuels category also includes fuels derived from synthetic crude, a substance similar to crude oil that is synthesized from natural resources like bitumen or oil shale [source: U.S. Energy Information Administration]. Chemically, synfuels are similar to the gasoline and diesel fuels we use today and can be used in existing engines. But producing them requires complex chemical conversions.

National governments and energy companies have been paying more attention to synthetic fuels in recent years, as rising oil prices and political instability in oil-producing countries have created incentives to seek out alternatives. The main benefit of synfuels is that they can be produced using substances like coal, natural gas and even plant waste, which are widely available. Many synfuels also burn cleaner than conventional fuel. But there are also disadvantages. While they can burn cleaner, producing synthetic fuels often causes just as much, if not more, pollution than traditional gasoline. Synfuels still remain more expensive to produce than conventional fuels, mostly because more research, development and investment are necessary to make production economically viable.

To find out about the different types of synthetic fuels currently being manufactured, keep reading.

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There may not be a magic bullet to solve the energy crisis, but synthetic fuels offer some advantages -- and drawbacks -- when compared to conventional fossil fuels. Find out about the different types of synthetic fuels and how they're processed.

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To understand how various feedstocks can be converted into liquid synthetic fuels, you first need to understand how fuel works. Oil, and products like gasoline made from oil, are made up of long chains of organic molecules called hydrocarbons (because they contain hydrogen and carbon). When those hydrocarbons are burned, they break down and release energy, which is used to fuel the engines in cars, trucks, planes, etc. Most organic material, including oil, coal, natural gas, plant waste and sewage, contains hydrocarbons. Today's engines were designed to work with oil-derived fuels like gasoline. In order for synthetic fuels to work in those engines, their hydrocarbons have to be restructured so they resemble the hydrocarbons found in petroleum and petroleum products.

There are basically two categories of synthetic fuels, synthetic crude oils ( syncrude), and Fischer-Tropsch liquids.The first category includes feedstocks and processes that are used to produce syncrude, or synthetic crude oil. Synthetic crude oil can be used for the same purposes as conventional crude oil. It is used as a raw material. Like conventional crude oil, syncrude must be refined and processed to make the various forms of petroleum-based commercial fuels like diesel, gasoline and kerosene.

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The three most popular sources of syncrude are extra-heavy oil, oil shale and oil sands. Each of those materials occurs naturally just like conventional oil, but they have different physical properties and amounts of impurities. For example, oil shale is a rock, and oil sands are a tarry mixture of sand and the oil-containing substance bitumen. These syncrude feedstocks are exposed to various levels of heat, pressure, and physical manipulation to produce a substance with the same arrangement of hydrocarbons as naturally occurring crude oil.

Processing syncrude feedstocks tends to harm the environment. Since they require more processing than crude oil, they create more CO ₂ emissions and other pollutants [source: U.S. Department of the Interior]. Also, collecting the feedstock often involves harmful environmental practices like strip mining. One advantage to syncrude fuels as an alternative to oil is that the world contains substantial untapped reserves of extra-heavy oil, oil shale and oil sands. Of course, like oil, those resources are not sustainable. They, too, will run out eventually.

Read on to learn about how Fischer-Tropsch synfuels are produced.

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To understand how various feedstocks can be converted into liquid synthetic fuels, you first need to understand how fuel works. Oil, and products like gasoline made from oil, are made up of long chains of organic molecules called hydrocarbons (because they contain hydrogen and carbon).

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Do You Want Biodiesel with That? - Chem Matters

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Do You Want Biodiesel with That? - Chem Matters

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How It's Made - Synthetic Rubber - Discovery Communications 

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How It's Made - Synthetic Rubber - Discovery Communications 

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How to make Synthetic Rubber {www downloadshiva com}

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How it's Made - Natural Rubber - Discovery Communications

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How it's Made - Natural Rubber - Discovery Communications

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A Brief History of Rubber - Akron Global Polymer Academy

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by Chris Woodford. Last updated: December 16, 2020.

Think of rubber and you probably think of elastic bands, car tires, or pencil erasers. But this super-stretchy material actually finds its way into tens of thousands of different products-everything from rubber stamps and waterproof shoes to surfing wetsuits, swimming caps, and dishwasher hoses. Rubber, which has been commonly used for over 1000 years, once came entirely from natural sources; now rubber products are just as likely to be made artificially in chemical plants. That's largely because we can't produce enough natural rubber to meet all our needs. And that, in turn, is because rubber is so fantastically useful. Let's take a closer look at one of the world's most amazing materials!

Photo: Half of the world's rubber is used to make vehicle tires-and at least half of them are wasted in landfills, burned in incinerators, or otherwise dumped.

What is rubber?

When people talk about "rubber", they don't usually specify what kind. There are many different kinds of rubber, but they all fall into two broad types: natural rubber (latex-grown from plants) and synthetic rubber (made artificially in a chemical plant or laboratory). Commercially, the most important synthetic rubbers are styrene butadiene (SBR), polyacrylics, and polyvinyl acetate (PVA); other kinds include polyvinyl chloride (PVC), polychloroprene (better known as neoprene), and various types of polyurethane. Although natural rubber and synthetic rubbers are similar in some ways, they're made by entirely different processes and chemically quite different.

Natural rubber

Photo: Rubber bands are a very familiar everyday use of latex rubber.

Natural rubber is made from a runny, milky white liquid called latex that oozes from certain plants when you cut into them. (Common dandelions, for example, produce latex; if you snap off their stems, you can see the latex dripping out from them. In theory, there's no reason why we couldn't make rubber by growing dandelions, though we'd need an awful lot of them.) Although there are something like 200 plants in the world that produce latex, over 99 percent of the world's natural rubber is made from the latex that comes from a tree species called Hevea brasiliensis, widely known as the rubber tree.

Photo: Guayule: one of many plants from which rubber can be made. Photo by Peggy Greb courtesy of US Department of Agriculture/Agricultural Research Service (USDA/ARS).

This latex is about one third water and one third rubber particles held in a form known as a colloidal suspension. Natural rubber is a polymer of isoprene (also known as 2-methylbuta-1,3-diene) with the chemical formula (C5H8)n. To put it more simply, it's made of many thousands of basic C5H8 units (the monomer of isoprene) loosely joined to make long, tangled chains. These chains of molecules can be pulled apart and untangled fairly easily, but they spring straight back together if you release them-and that's what makes rubber elastic.

Synthetic rubbers

Synthetic rubbers are made in chemical plants using petrochemicals as their starting point. One of the first (and still one of the best known) is neoprene (the brand name for polychloroprene), made by reacting together acetylene and hydrochloric acid. Emulsion styrene-butadiene rubber (E-SBR), another synthetic rubber, is widely used for making vehicle tires.

For the rest of this article, we'll concentrate mostly on natural rubber.

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How is rubber made?

Photo: In 1839, American inventor Charles Goodyear (1800-1860) developed the vulcanization (heat-treatment) process that makes rubber harder and more durable. He'd spent many years as a struggling inventor, trying desperately to turn rubber into a useful product, when he accidentally dropped some rubber on a hot stove and watched it "cook" itself into a much more useful form: the black, vulcanized material most of us know as rubber to this day. Despite developing one of the most useful materials of all time, Goodyear never made much money from his invention and died deeply in debt. Fortunately, his name lives on in the Goodyear tire company-and his superb contribution to materials technology has never been forgotten. Photo courtesy of US Library of Congress.

It takes several quite distinct steps to make a product out of natural rubber. First, you have to gather your latex from the rubber trees using a traditional process called rubber tapping. That involves making a wide, V-shaped cut in the tree's bark. As the latex drips out, it's collected in a cup. The latex from many trees is then filtered, washed, and reacted with acid to make the particles of rubber coagulate (stick together). The rubber made this way is pressed into slabs or sheets and then dried, ready for the next stages of production.

By itself, unprocessed rubber is not all that useful. It tends to be brittle when cold and smelly and sticky when it warms up. Further processes are used to turn it into a much more versatile material. The first one is known as mastication (a word we typically use to describe how animals chew food). Masticating machines "chew up" raw rubber using mechanical rollers and presses to make it softer, easier to work, and more sticky. After the rubber has been masticated, extra chemical ingredients are mixed in to improve its properties (for example, to make it more hardwearing). Next, the rubber is squashed into shape by rollers (a process called calendering) or squeezed through specially shaped holes to make hollow tubes (a process known as extrusion). Finally, the rubber is vulcanized (cooked): sulfur is added and the rubber is heated to about 140°C (280°F) in an autoclave (a kind of industrial pressure cooker).

Photo: Vulcanized rubber is heated in a giant sealed "cooker" like this one, used for making earthmover tires, pictured at Firestone Tire Company in 1942. At that time, it was the biggest rubber vulcanizer in the world, standing some 2.5 stories high when opened wide. I've colored the people in the pictures red to give you an idea of the scale. Photos by Alfred T. Palmer courtesy of US Library of Congress.

Where does rubber come from?

As its name suggests, the rubber tree Hevea brasiliensis originally came from Brazil, from where it was introduced to such countries of the Far East as Malaysia, Indonesia, Burma, Cambodia, China, and Vietnam. During World War II, supplies of natural rubber from these nations were cut off just when there was a huge demand from the military-and that accelerated the development of synthetic rubbers, notably in Germany and the United States. Today, most natural rubber still comes from the Far East, while Russia and its former republics, France, Germany, and the United States are among the world's leading producers of synthetic rubber. The world's largest single source of latex rubber is the Harbel Rubber Plantation near Monrovia in Liberia, Africa established in the 1920s and 1930s by the Firestone tire company.

Charts: Left: Where does rubber come from? Almost three quarters of the world's rubber is produced in Asia, with the rest split mostly between Europe (including Russia) and the Americas. Almost all of the rubber produced in Africa (which, here, includes the Middle East) is natural, whereas most American and all European-produced rubber is synthetic. Asia produces roughly 60% natural and 40% synthetic rubber. Right: Overall, the world now produces more synthetic than natural rubber. Both charts drawn using the latest available data from the International Rubber Study Group, 2020.

How does vulcanization make rubber stronger?

Artwork: Top: Natural, latex rubber is easy to pull apart because the long polymer molecules it contains (made from carbon and hydrogen atoms) are only weakly linked together. Bottom: When natural rubber is cooked with sulfur, the sulfur atoms form extra cross-links (shown here as yellow bars) "bolting" the molecules together and making them much harder to pull apart. This process is called vulcanization and it makes the strong, durable, black rubber we see on things like car tires.

Rubber-the kind you get from a tree-starts off as white and runny latex. Even when it's set into a product, this latex-based, natural rubber is very squashy, pretty smelly, and not very useful. The kind of rubber you see in the world around you, in things like car and bicycle tires, is vulcanized: cooked with sulfur (and often other additives) to make it harder, stronger, and longer lasting.

So what's the difference between raw, latex rubber and cooked, vulcanized rubber? In its natural state, the molecules in rubber are long chains that are tangled up and only weakly linked together. It's relatively easy to pull them apart-and that's why latex rubber is so stretchy and elastic. When latex is vulcanized, the added sulfur atoms help to form extra bonds between the rubber molecules, which are known as cross-links. These work a bit like the trusses you see on a bridge, tying the molecules together and making them much harder to pull apart.

What do we use rubber for?

Photo: Three everyday uses of rubber. Top: A latex pencil eraser; Middle: the tough vulcanized rubber drive belt from a vacuum cleaner; Bottom: the waterproof rubber gasket that seals a washing machine door tight.

The physical and chemical properties of a material dictate what we use it for. Even if you know absolutely nothing about the real-world uses of rubber, you can probably make some very good guesses. For example, everyone knows rubber is strong, stretchy, flexible (elastic), durable, and waterproof, so it's no surprise to find it used in things like waterproof clothes and wellington boots, sticking plasters, and adhesives.

The most important use of rubber is in vehicle tires; about half of all the world's rubber ends up wrapped around the wheels of cars, bicycles, and trucks! You'll find rubber in the hard, black vulcanized outsides of tires and (where they have them) in their inner tubes and liners. The inner parts of tires are usually made from a slightly different, very flexible butyl rubber, which is highly impermeable to gases (traps them very effectively), so tires (generally) stay inflated for long periods of time.

Photo: Swimming caps like this are made from soft and stretchy latex rubber.

The fact that rubber can be made either soft or hard greatly increases the range of things we can use it for. Soft and stretchy latex is used in all kinds of everyday things, from pencil erasers, birthday balloons, and condoms to protective gloves, adhesives (such as sticky white PVA), and paints. Harder rubbers are needed for tougher applications like roofing membranes, waterproof butyl liners in garden ponds, and those rigid inflatable boats (RIBs) used by scuba divers. Because rubber is strong, flexible, and a very poor conductor of heat and electricity, it's often used as a strong, thin, jacketing material for electrical cables, fiber-optic cables, and heat pipes. But the range of applications is truly vast: you'll find it in everything from artificial hearts (in the rubber diaphragms that pump blood) to the waterproof gaskets that seal the doors on washing machines!

Neoprene (polychloroprene) is best known as the heat-insulating, outer covering of wetsuits -but it has far more applications than most people are aware of. Medical supports of various kind use it because, tightly fitted, it compresses and warms injured bits of your body, promoting faster healing. Since it's flexible and waterproof, it's also widely used as a building material, for example, as a roof and floor sealant, and as a spongy absorber of sound and vibration in door and window linings.

Although the world has a vast appetite for new rubber, we also produce a huge quantity of rubber waste, especially from discarded vehicle tires-and that's becoming an important raw material in its own right. According to the Rubber Manufacturers Association, the United States alone produced almost 270 million waste rubber vehicle tires in 2011, which is about a third of all the tires used worldwide. While some of these are retreaded and others are ground up to make a low-grade aggregate that can be used for the floors in things like children's playgrounds, over half of them are wasted (either burned as a fuel or buried in landfills). Rubber manufacturers have recently turned their attention to recycling tires in all kinds of new ways, making everything from mouse mats and sports bags to shoe soles and car components.

Photo: Half of all rubber is used in vehicle tires, and hundreds of millions are wasted each year. I've made a very slight difference to the problem by buying this recycled rubber mouse mat, made from an old car tire. It's colored black because it's made from hard vulcanized rubber.

A brief history of rubber

1000CE: Indians living in Central and South America have learned how to made waterproof clothes and shoes using latex from rubber trees. They call rubber trees "cahuchu" (crying wood), which is why the French still call rubber caoutchouc (pronounced "cow-chew") today.

1731: During an expedition to South America, French explorer Charles Marie de La Condamine (1701-74) sends back samples of rubber to Europe, prompting intense scientific interest.

1770: The discoverer of oxygen, English scientist Joseph Priestley (1733-1804), finds he can use pieces of rubber to erase the marks made by pencil on paper. In England, erasers are still widely called "rubbers" today.

1791: Englishman Samuel Peal develops a method of waterproofing cloth with a rubber solution.

1818: Scottish medical student James Syme (1799-1870) uses rubber-coated cloth to make raincoats.

1823: Scotsman Charles Macintosh learns of Syme's discovery, refines it, and patents it, earning fame and fortune as the inventor of the rubberized, waterproof coat. Waterproof coats have been known as "Mackintoshes" (with a slight variation of spelling) ever since.

1829: English chemist and physicist Michael Faraday (1791-1867) analyzes samples of Hevea and works out that the chemical formula for isoprene-type rubber is C5H8.

1839: American inventor Charles Goodyear (1800-1860) accidentally discovers how to vulcanize rubber after dropping a piece of the material (which has been treated with sulfur) onto a hot stove.

1830s~1840s: Botanist Thomas Lobb discovers a rubbery substance called Gutta-percha (Palaquium gutta) in Malaysia;Dr William Montgomerie, a surgeon working in the same region, sends samples back to Britain in 1843. According to a contemporaryaccount by William Dalton, it has "remarkable properties, vast utility, and application to scientific and ornamental purposes" in everything from "boots and shoes" to "prevention of toothache."

1876: Intrepid English explorer Sir Henry Wickham (1846-1928) smuggles thousands of seeds from the rubber treeHevea brasiliensis out of Brazil and back to England. The English grow the seeds atKew Gardens just outside London and export them to various Asian countries, establishing the giant plantations that now supply much of the world's rubber.

1877: US rubber manufacturer Chapman Mitchell develops the first commercial process for recycling rubber from scratch.

1882: John Boyd Dunlop (1840-1921) invents thepneumatic (air-filled) rubber tire. The development of gasoline-powered cars with rubber tires leads to a huge increase in the need for rubber.

1883: US chemist George Oenslager (1873-1956) develops a much faster way of vulcanizing rubber using chemicals called organic (carbon-based) accelerators.

1906-12: Bayer, a German chemical company, develops methyl rubber (a polymer of methylisoprene). It becomes critically important to Germany during World War I when supplies of natural rubber are cut off, but falls out of fashion when better alternatives are eventually developed.

1910: English Chemist S.S. Pickles becomes the first person to propose (correctly) that rubber consists of long chains of isoprene. Technically, Hevea has the chemical name cis-1,4-polyisoprene, while Gutta-percha is a variation known as trans-1,4-polyisoprene.

1930: German chemical company IG Farben develops a type of general-purpose, synthetic rubber named Buna-S ("bu" from butadiene, "na" from the chemical symbol for sodium, and "S" for styrene). Technically, it's a copolymer of butadiene (75 percent) and styrene (25 percent), which is why it's now more generally known as styrene-butadiene or styrene-butadiene-rubber (SBR); it's also sold under tradenames such as Goodyear's Neolite®. Today, styrene-butadiene remains by far the world's most important synthetic rubber.

1930: A team of US chemists at the DuPont company, led by Wallace Carothers (1896-1937), develop a revolutionary synthetic rubber called polychloroprene and sold as neoprene. (Shortly afterward, the same group developed an even more revolutionary material:nylon.)

1940s: Synthetic rubbers are produced in the United States for the first time by companies such as Firestone, Goodyear, and Goodrich.

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Articles

The horrific consequences of rubber's toxic past by Tim Harford. BBC News, July 24, 2019. A detailed look at the controversial history of rubber.

Goodyear's Illuminated Tires Promised a Whole New Frontier in Car Fashion by Evan Ackerman. IEEE Spectrum, February 28, 2017. The fascinating story of Neothane car tires that lit up in the dark.

Why we still (can't) live without rubber by Charles C. Mann. National Geographic, December 2015, July 24, 2019. Where in the world does our rubber come from?

In Thailand, Rubber Price Plunge Has Political Cost by Thomas Fuller. The New York Times, August 29, 2013. It's easy to forget that commodities like rubber provide a living for many of the world's people. What happens to their lives as prices rise and fall?

Recipe for Green Tires: Plants, Not Petroleum by Steven Ashley. The New York Times, June 18, 2010. From recycling to new kinds of synthetic rubber, this article explores the various ways of reducing the environmental impact of vehicle tires.

U.S. Synthetic Rubber Program: National Historic Chemical Landmark: American Chemical Society, 1998. A detailed account of the history of synthetic rubber in Germany and (later) the United States.

Books

For older readers

A World History of Rubber: Empire, Industry, and the Everyday by Stephen L. Harp. John Wiley & Sons, 2016. A short (184-page) but wide-ranging introduction that puts rubber in a global context.

Rubber Technology by Maurice Morton. Springer, 1999. Explains the basic science of rubber polymers before looking at natural and synthetic rubbers.

Rubber Compounding: Principles: Materials, and Techniques, Second Edition by Fred Barlow. CRC Press, 1993. A detailed guide to manufacturing rubber compounds using a variety of additives.

Natural Rubber: Biology, Cultivation and Technology by M.R. Sethuraj (Editor) and Ninan T. Mathew. Elsevier, 1992. A detailed, very comprehensive guide to rubber as a crop, including related topics such as guayule.

For younger readers

Rubber versus Glass: I Wonder Why by Laurence Lowry. NSTA, 2014. A 36-page introduction to the contrasting properties of two everyday materials, for ages 5-8.

Rubber by Cassie Mayer. Heineman, 2008. A basic 24-page introduction probably best for ages 6-9.

Rubber by Chris Oxlade. Pearson Education, 2003. A 32-page introduction for ages 9-12.

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Advertisement by Chris Woodford. Last updated: December 16, 2020. Think of rubber and you probably think of elastic bands, car tires, or pencil erasers. But this super-stretchy material actually finds its way into tens of thousands of different products-everything from rubber stamps and waterproof shoes to surfing wetsuits, swimming caps, and dishwasher hoses.

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U.S. Synthetic rubber Program - National Historic Chemical Landmark

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U.S. Synthetic rubber Program - National Historic Chemical Landmark

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Industry, Academe, and Government Partnershipo Solves the Rubber Supply Crisis

The technology chosen for synthetic rubber production was based on Buna S research because Buna S could be mixed with natural rubber and milled on the same machines, and because the raw materials (the monomers) were available. This rubber was particularly suited for tire treads because it resisted abrasive wear; and it retained sharper impressions in molds, calender rolls, and extruders than natural rubber. However, the synthetic rubber was more difficult to make, had less tackiness, and required more adhesive in making a tire than natural rubber. These problems had to be overcome to produce a reliable general purpose rubber.

On March 26, 1942, the representatives of the companies and the U.S. government agreed upon a "mutual recipe" to produce the GR-S rubber. The recipe consisted of monomers butadiene (75%) and styrene (25%), potassium persulfate as a catalyst or initiator, soap as an emulsifier, water, and a modifier, dodecyl mercaptan. Because GR-S required different compounding conditions, accelerators, antioxidants, and types and amounts of carbon black than natural rubber, the program's leaders realized that a research and development program would be necessary to solve the existing and potential problems of GR-S manufacture.

Robert R. Williams of Bell Telephone Laboratories organized and coordinated the rubber industry research effort, which included participation by the National Bureau of Standards, Bell Labs, and such major research universities as the University of Illinois, University of Minnesota, and University of Chicago. The first of many Copolymer Research Committee meetings was held December 29, 1942, in Akron, Ohio, to share the latest information among the organizations working on the various aspects of synthetic rubber research. In addition to representatives from the government, the major companies, and universities, there were contributors from Columbian Carbon Company, Case School of Applied Science (now Case Western Reserve University), Princeton University, and The University of Akron. The affiliations of the attendees at this meeting demonstrate the wide participation in the program. Phillips Petroleum, General Tire, the Polymer Corporation, and Cornell University delegates were at later meetings.

During the combined effort, the companies shared the findings of more than 200 patents. Participating U.S. scientists and engineers improved the polymerization process, produced modifiers that allowed existing processing equipment to equal natural rubber production rates, specified carbon black grades for specific applications, and modified butadiene production to improve efficiency. University laboratories developed better analytical methods to achieve better quality control and performed fundamental research on the mechanism of GR-S polymerization and the chemical structure of rubber. Academic and industrial contributors clarified the factors that influenced the polymerization rate, polymer molecular weight, and weight distribution.

The rubber companies had the technology and the responsibility to build the plants to produce synthetic rubber. The government provided an equally important component, the capital. W. I. Burt, a B. F. Goodrich engineer, chaired the committee that designed and built the first government GR-S plant. Walter Piggot, also from Goodrich, chaired the engineering committee for GR-S production.

Several plants were scattered across the country, some for polymerization, others for the production of the monomers. The initial plants were built and brought on-stream in a record time of nine months.

Firestone produced the program's first bale of synthetic rubber on April 26, 1942, followed by Goodyear on May 18, United States Rubber Corporation on September 4, and Goodrich on November 27. In 1942, these four plants produced 2,241 tons of synthetic rubber. By 1945, the United States was producing about 920,000 tons per year of synthetic rubber, 85 percent of which was GR-S rubber. Of that 85 percent, the four major companies were producing 547,500 tons per year (70%).

Research continued after the war ended in August 1945. Synthetic rubber was improved and, after the wartime plants served again during the Korean Conflict, became an integral part of the rubber industry. GR-S production returned to private hands in 1955 when the government sold the plants. As the 20th century draws to a close, the rubber industry has grown to a $60 billion international enterprise with about 15,000 establishments operating in the United States. Synthetic rubber is a vital part of the transportation, aerospace, energy, electronics, and consumer products industries.

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U.S. Synthetic Rubber Program - National Historic Chemical Landmark - American Chemical Society

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American Chemical Society: Chemistry for Life.

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The Chemistry of Artificial Sweeteners - Discover

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The Chemistry of Artificial Sweeteners - Discover

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In the past year, shares of Tate & Lyle, one of the world's largest manufacturers of sweeteners, have nearly doubled in price. And sugar has had nothing to do with it. The company sold its stake in Domino Sugar four years ago, then came up with something much more profitable: sucralose, also known as Splenda. The sweetener is sold in yellow boxes and sachets with royal-blue script reminiscent of Domino's packaging. "Made from sugar, so it tastes like sugar," the slogan claims, but like all other sugar substitutes, sucralose was born in a laboratory. The country's entire supply is produced in one well-guarded and famously secretive facility in Alabama, where truckloads of common table sugar are shipped in weekly, to be modified via a complex chemical process involving chlorine and phosgene gas. The result is so intensely sweet that Tate & Lyle has to cut it with 600 parts filler to approximate a natural sweetness.

What can make a chemical so sweet? And is it bad for us? The questions aren't trivial: Eight out of 10 Americans now consume some sort of artificial sweetener. Last year alone the food industry introduced 2,225 reduced-sugar and sugar-free foods, many of them made with sucralose. Chemical additives are nothing new, of course-most processed foods contain more than one artificial flavoring, emulsifier, coloring, or gelling agent-and sugar substitutes are among the most-studied additives in the world. Yet rumors of their side effects persist, and their escalating potency demands attention.

"There are a lot of people who have been looking for the perfect sweetener for a long time," says Eric Walters, a biochemist at Rosalind Franklin University of Medicine and Science in Chicago. Walters himself has studied artificial sweeteners for nearly 25 years, so he's well aware of the central irony of his field: The most successful sugar substitutes have all been discovered by accident. Saccharin was invented in Baltimore about 130 years ago by two chemists at Johns Hopkins University who were experimenting with coal-tar derivatives. Aspartame was found in the 1960s by a medical chemist in Illinois who was investigating a drug for gastric ulcers. Sucralose was discovered in 1976 by a graduate student at King's College London. His head researcher had told him to test some compounds, but he misunderstood and tasted them instead.

Of the three sweeteners, sucralose has been touted as the most natural, but that claim "has more to do with clever marketing than with chemistry," Walters says. Although sucralose is made from sugar, its chemical structure is significantly different: A molecule of the artificial sweetener has three chlorine atoms, whereas sugar has three pairs of oxygen and hydrogen atoms. By contrast, the only unnatural component in aspartame is a methyl ester bond that connects phenylalanine and aspartic acid, two amino acids abundant in the human body. The body's digestive enzymes recognize aspartame as a protein and break it down much as they would a natural compound. Sucralose, on the other hand, slips through undigested, as does saccharin-a compound of carbon, nitrogen, oxygen, and sulfur atoms. "The body doesn't know what to make of it, so it doesn't make anything," Walters says.

How can such different structures all taste sweet? Until very recently, the answer was anyone's guess. Thousands of sweet-tasting compounds belonging to more than 150 chemical classes have been discovered, including low-molecular-weight carbohydrates, aminoacyl sugars, amino acids, peptides, proteins, terpenoids, chlorinated hydrocarbons, halogenated sugars, N-sulfonyl amides, sulfamates, polyketides, anilines, and ureas. Scientists have long known that our taste buds contain receptors that react to all these compounds, but no one knew exactly how they worked.

Then four years ago Charles Zuker, a rather aptly named neuroscientist at Howard Hughes Medical Institute, made a startling announcement: All the sweet things in life are perceived by a single receptor. Zuker used the human and mouse genomes to isolate genes associated with taste. He found more than 30 that code for bitter receptors but only a single receptor devoted to sweet. "Evolutionarily, it makes sense," says Grant DuBois, a chemist for Coca-Cola. "The theory being that there are a lot of varyingly toxic bitter compounds we have to know how to distinguish between, but everything sweet can be lumped together as good."

The one-receptor theory had a lot of explaining to do. The biggest problem was what corporate chemists call synergy. "If you ever look at the sweeteners in sugar-free gum, you'll notice that there's nearly always a list," DuBois says. That's because certain sweeteners amplify one another. When you add saccharin to, say, cyclamate (a compound of carbon, oxygen, sulfur, and nitrogen), as in the original Tab recipe, the result is notably sweeter than if you simply add up the sweetening power of each. "Synergy is a well-known phenomenon in drug design, and it always means at least two receptors working together," DuBois says. By the same token, factors such as temperature (cold) and caffeine can inhibit some sweeteners but not others, which also suggests that multiple receptors are at work. Still, Zuker was adamant: Knock out either of the two subunits on the protein receptor he identified and laboratory mice lose all sense of sweet, regardless of which compounds they're given.

But what if each subunit had its own binding site, Zuker wondered? Finally, last September, biochemists from Senomyx (a company cofounded by Zuker) proved him right. There is only one sweet receptor, they concluded. But unlike any other receptor in the body, it has more than one region that can be activated by different molecules. "It's like having a gun with two triggers," DuBois says.

Chemists have only begun to tap this receptor's true potential. Cyclamate is 45 times as sweet as sugar, aspartame and saccharin are 180 and 300 times as sweet, respectively, and sucralose is 600 times sweeter. But the next generation of aspartame, known as neotame, is 13,000 times as sweet as sugar, and other compounds have been isolated that are more than 100,000 times as sweet. "The differences are because the molecules have different affinities," Walters says. Sucralose, for instance, fits more snugly in the receptor than sucrose, partly because its chlorine atoms carry a stronger charge than the oxygen atoms they replaced. Neotame, which was recently approved by the FDA, locks in so tightly it keeps the receptor firing like a machine gun.

Even when they've been cut with fillers, none of these sweeteners can truly pass for sugar. Saccharin has a disconcertingly metallic aftertaste-not, thankfully, because it leaches aluminum from cans but because it also triggers bitter and sour receptors. Aspartame and neotame are fragile molecules that break down relatively quickly on supermarket shelves and can't withstand the heat of cooking. Sucralose can take the heat and is stable, but it lacks the bulk, the browning ability, and the "mouthfeel" of real sugar.

That these sweeteners were invented by chemists has long made them suspect. Saccharin was listed as an "anticipated human carcinogen" in 1981, sucralose has been shown to weakly mutate genes in test tubes, and aspartame has triggered fears about everything from autism to multiple sclerosis. Still, no concerns have held up under scrutiny. Food additives have to meet much higher standards than drugs, Walters points out, because their drawbacks aren't weighed against their medical benefits. Aspartame, for instance, has been studied more than any other substance in FDA history, yet it has consistently been declared safe. Sucralose has shown no carcinogenic effects in animals, even at high doses. And saccharin was rehabilitated as a safe additive in 1997, when scientists found that rats used in earlier studies had a predisposition to cancer unrelated to the sweetener.

The best reason to be sour on artificial sweeteners is more familiar. Although sucralose and saccharin aren't absorbed by the body, they're not quite calorie-free: The dextrose and maltodextrin that manufacturers use to bulk them up contain about a quarter of the calories found in sugar. And although diabetics choose sugar substitutes over sucrose, animal studies suggest that artificial sweeteners can also trigger the release ofinsulin-albeit in much smaller quantities. Studies show that people who drink sugar-free sodas can lose more weight than those who drink regular sodas, but some nutritionists worry that catering to the body's craving for sweets will only increase the appetite for them. Sugar by any other name is still best in small doses.

How sweet it is
The relative potency of sugar compared with artificial sweeteners.
sugar 1x
cyclamate 45x
aspartame 180x
saccharin 300x
sucralose 600x
neotame 13,000x

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The Chemistry of . . . Artificial Sweeteners

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In the past year, shares of Tate & Lyle, one of the world's largest manufacturers of sweeteners, have nearly doubled in price. And sugar has had nothing to do with it. The company sold its stake in Domino Sugar four years ago, then came up with something much more profitable: sucralose, also known as Splenda.

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Artificial Sweetener Persists in the Environment - American Chemical Society, Environmental Science and Technology

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Artificial Sweetener Persists in the Environment - American Chemical Society, Environmental Science and Technology

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Real or Fake Sugar - Does It Matter - CNN Health

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Real or Fake Sugar - Does It Matter - CNN Health

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real or fake sugar: does it matter? - cnn

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Real or fake sugar: Does it matter? - CNN

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Are artificial sweeteners used in soft drinks and foods safe? Will they make us fat? How much is too much? We spoke to researchers who had some clues.

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Sugar vs. Artificial Sweeteners - Scientific American 

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Sugar vs. Artificial Sweeteners - Scientific American 

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Dear EarthTalk: I saw an article on sugar's effects on the environment. Has anyone compared different sweeteners (artificial or natural) for their environmental impacts?-Terri Oelrich, via e-mail

The production of sugar has indeed taken a huge environmental toll. "Sugar has arguably had as great an impact on the environment as any other agricultural commodity," reports the World Wildlife Fund (WWF), citing biodiversity loss as a result of the "wholesale conversion of habitat on tropical islands and on coastal areas" to grow sugar. WWF adds that the cultivation of sugar has also resulted in considerable soil erosion and degradation and the use of large amounts of chemicals across the tropics and beyond.

Some natural food markets now carry sustainably harvested sugar that does not fit this profile, though sugar's ugly history has led many eco-conscious consumers to look elsewhere to satiate their sweet teeth. Fortunately there are several natural and artificial options that are safe to eat and relatively benign for the environment. Perhaps the most popular choice is stevia, a sustainably harvested herb from Latin America that is 30 times sweeter than table sugar but without calories. Other natural alternatives include coconut palm sugar, barley malt syrup, brown rice syrup, agave nectar, maple syrup and raw honey. These choices may not save on calories like stevia, but they do sweeten without environmental guilt.

As for synthetic sugar alternatives, there has been considerable talk of how dangerous they may be for our health, but little evidence of harm has actually come forth and their environmental impacts may be more reason for concern. Aspartame, for example, used in Equal and also in diet sodas, is made by fermenting corn and soy, the two biggest genetically engineered crops in the U.S. Environmentalists are concerned that such tinkering with nature could have unexpected and potentially disastrous results down the road.

Another common sugar alternative, sucralose (trade name Splenda) has its issues, too. A study released in 2013 by researchers from the University of North Carolina (UNC) found that the majority of Splenda used around the world ends up in the Gulf Stream, the fast-moving ocean current that starts in the Gulf of Mexico and flows into the Atlantic Ocean and beyond into the coastal waters of Europe and Africa.

"Sucralose cannot be effectively broken down by the bacteria in the human digestive tract," reports UNC. "As a result, the body absorbs little or no calories and 90 percent of the chemical compound leaves the body through human waste and enters sewage systems." Since this sucralose cannot be broken down by most water treatment systems, it ends up in the oceans, where the long-term effects remain unknown.

Saccharin (trade name Sweet'N Low) got a bad rap in the 1970s when rats exposed to large amounts got bladder cancer, but it has since been vindicated: The Food & Drug Administration removed warning labels in 2000 and the Environmental Protection Agency removed it from its lists of hazardous constituents and commercial chemical products in 2010. Nonetheless, saccharin can cause problems for pregnant women and infants who consume large amounts, and also gets a veto as a petroleum derivative.

CONTACTS: WWF, ; "Fake sweetener Splenda fills our oceans, scientists find," www.naturalnews.com/039156_splenda_ocean_pollution_environment.html, "The Sweet Side of Fair Trade," Green America, www.greenamerica.org/livinggreen/SweetFairTrade.cfm.

EarthTalk® is written and edited by Roddy Scheer and Doug Moss and is a registered trademark of E - The Environmental Magazine (www.emagazine.com). Send questions to: earthtalk@emagazine.com. Subscribe: www.emagazine.com/subscribe. Free Trial Issue: www.emagazine.com/trial.

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Dear EarthTalk : I saw an article on sugar's effects on the environment. Has anyone compared different sweeteners (artificial or natural) for their environmental impacts? -Terri Oelrich, via e-mail The production of sugar has indeed taken a huge environmental toll.

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Get access to files anywhere through secure cloud storage and file backup for your photos, videos, files and more with Google Drive.

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Kevlar - How Bulletproof are Bulletproof Vests? - How Stuff Works

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Kevlar - How Bulletproof are Bulletproof Vests? - How Stuff Works

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Advertisement

In August 2017, 30-year-old New York Police Department officer Hart Nguyen was shot while responding to a call regarding a 29-year-old Andy Sookdeo, an emotionally distraught man. As Nguyen approached the door to a bedroom where Sookdeo had barricaded himself, he was shot three times - once in the arm, and twice in his bulletproof vest. He survived. "His vest definitely saved his life," tweeted NYPD Police Commissioner James O'Neill after the attack.

In 2016, 23-year-old Joaquin Mendez of Tampa, Florida, was killed by a gunshot to the chest. According to the local CBS affiliate, Mendez sat in a chair, put on a bulletproof vest, and wondered if it worked. His friend, 24-year-old Alexandro Garibaldi, pulled out a pistol and shot the vest to find out. The bullet pierced the vest and killed Mendez.

As these two stories demonstrate, bulletproof vests do indeed save lives, but they are not always, um, bulletproof or perfect. Do bulletproof vests degrade over time, and can they fail?

First, a Bit of History

Early bulletproof vests were mainly made from poly-paraphenylene terephthalamide - better known as Kevlar. It was invented by Stephanie Kwolek, a chemist working for DuPont in the early 1960s.

DuPont had already invented Nylon and Spandex and was on the hunt for the next generation of high-performance fibers. Synthetic fibers are created with polymers - large molecules composed of repeating subunits, effectively creating a chain of molecules. Nylon, for instance, is a polymer made from hexamethylenediamine, an organic compound, and adipic acid, an ingredient often found in Jell-O. Kevlar is made from molecules para-phenylenediamine, often used in antioxidants and as dyes, and terephthaloyl chloride.

What Kwolek discovered would eventually become Kevlar and would see application in tires, racing sails and bulletproof vests.

Bulletproof vests today are made from polyethylene fibers - a popular plastic polymer seen in nearly everything we use: grocery bags, toys, plastic trash bins and so on. Polyethylene fibers (or "PE" as it's called), are woven in layers to form the guts of a protective vest that is cheaper and stronger than Kevlar. In 1989, AlliedSignal developed a competitor for Kevlar and called it Spectra Shield. Originally used for sail cloth, the polyethylene fiber is now used to make lighter, yet stronger, non-woven material for use in bulletproof vests alongside the traditional Kevlar.

Different Vests for Different Guns

According to Tom Nardone, president and founder of BulletSafe, a manufacturer of bulletproof vests, the layers inside a vest are designed to reduce the velocity of a round to a point below supersonic - faster than the speed of sound - so the fibers can have time to react to the bullet and exert their toughness on the bullet. The more layers, or the greater the density of the weaving of layers, the greater the toughness of the fibers - a measure of their strength and how much they will bend before they break - and the more capable they are of stopping a bullet.

Most pistols fire bullets at velocities that are slightly above the speed of sound. A bullet from a 9mm travels around 984 feet (380 meters) per second, roughly 164 feet/second (50 meters/second) faster than the speed of sound. Slugs from shotguns travel even slower. A good vest doesn't need to work hard to bring a 9mm bullet or shotgun shell's velocity down to a point where it can make use of the toughness of its fibers.

A rifle bullet, however, is another matter entirely. Depending on the grain and quality of the propellant, a bullet fired from an AR-15 travels, roughly, 3,300 feet/second (1,005 meters/second), nearly three times the speed of sound. It'll take a far greater density of ballistic fiber to stop that bullet.

"Supersonic rounds need plates to shatter the bullet into pieces," Nardone says. Most vests designed to stop rifle bullets are backed up with high density insert plates made from ceramics and polyethylene to break up a bullet into pieces and capture it.

"A PE vest with a [rifle] round, that bullet would be going faster than the speed of sound for so long that it would go through until the vest failed," Nardone says.

The material of the vests themselves is also prone to break down for various reasons. Kevlar, for instance, degrades when exposed to salt - such as the salt in human sweat. The longer a person exerts themselves while in a bulletproof vest made of Kevlar - to the tune of years - the greater the likelihood of failure. Vests made from PE also will break down over time when exposed to UV light.

"There is a five-year lifespan on vests. Sometimes people are buying older, used vests, mostly police-work vests, [from back when] they didn't have as high a level of protection," Nardone says.

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Advertisement In August 2017, 30-year-old New York Police Department officer Hart Nguyen was shot while responding to a call regarding a 29-year-old Andy Sookdeo, an emotionally distraught man. As Nguyen approached the door to a bedroom where Sookdeo had barricaded himself, he was shot three times - once in the arm, and twice in his bulletproof vest.

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by Chris Woodford. Last updated: February 25, 2020.

Nature has given us some amazing materials. There's wood: a material so strong and versatile you can use it for everything from making paper to building houses. There's also wool, with insulation so effective it lets sheep stand outside in the snow all winter. Or how about skin: a material that will repair itself automatically and often completely invisibly in only a matter of days? Truly incredible though these materials are, they're far from perfect for every application, especially in the modern world where the challenges we face are ones nature could never have anticipated. That's why we now rely on synthetic materials such as Kevlar®. It's a plastic strong enough to stop bullets and knives-often described as being "five times stronger than steel on an equal weight basis." It has many other uses too, from making boats and bowstrings to reinforcing tires and brake pads. Let's take a closer look at how it's made and what makes it so tough!

Photo: Super-strong Kevlar is best known for its use in body armor-and this photo shows you why: it's a piece of Kevlar after being hit by a projectile. You can see a dent (coming up toward the camera)-but you can't see a hole. You might be bruised by this impact (or suffer what's called a "blunt trauma" injury), but you wouldn't die. Picture courtesy of US Army.

What exactly is Kevlar?

Kevlar is one of those magic modern materials people talk about all the time without ever really explaining any further. "It's made of Kevlar", they say, with a knowing nod, as though that were all the explanation you needed.

Kevlar is simply a super-strong plastic. If that sounds unimpressive, remember that there are plastics-and there are plastics. There are literally hundreds of synthetic plastics made by polymerization (joining together long chain molecules) and they have widely different properties. Kevlar's amazing properties are partly due to its internal structure (how its molecules are naturally arranged in regular, parallel lines) and partly due to the way it's made into fibers that are knitted tightly together.

Photo: Kevlar textiles get their properties partly from the inherent strength of the polymer from which the fibers are made and partly from the way the fibers are knitted tightly together, as shown here in a NASA ballistics test. Picture courtesy of NASA Glenn Research Center (NASA-GRC).

Kevlar is not like cotton-it's not something anyone can make from the right raw materials. It's a proprietary material made only by the DuPont™ chemical company and it comes in two main varieties called Kevlar 29 and Kevlar 49 (other varieties are made for special applications). In its chemical structure, it's very similar to another versatile protective material called Nomex. Kevlar and Nomex are examples of chemicals called synthetic aromatic poly amide s or aramids for short. Calling Kevlar a synthetic aromatic polyamide polymer makes it sound unnecessarily complex. Things start to make more sense if you consider that description one word at a time:

Synthetic materials are made in a chemical laboratory (unlike natural textiles such as cotton, which grows on plants, and wool, which comes from animals).

Aromatic means Kevlar's molecules have a strong, ring-like structure like that of benzene.

Polyamide means the ring-like aromatic molecules connect together to form long chains. These run inside (and parallel to) the fibers of Kevlar a bit like the steel bars ("rebar") in reinforcedconcrete.

Polymer means that Kevlar is made from many identical molecules bonded together (each one of which is called a monomer).Plastics are the most familiar polymers in our world. As we've seen, the monomers in Kevlar are based on a modified, benzene-like ring structure.

Like Nomex, Kevlar is a distant relative of nylon, the first commercially successful "superpolyamide", developed by DuPont in the 1930s. Kevlar was introduced in 1971, having been discovered in the early 1960s by US chemist Stephanie Kwolek (1923-2014), who earned US Patent 3,287,323 for her invention, with Paul Morgan, in 1966. Originally developed as a lightweight replacement for steel bracing in vehicle tires, it's probably best-known today for its use in things like body armor; by the time of Kwolek's death in 2014, one million Kevlar body vests had been sold-and countless lives saved.

What's so good about Kevlar?

Photo: Braided Kevlar can be used to make super-strong rope. Compared on a strength-to-weight ratio, Kevlar about 5-6 times stronger than steel wire and twice as strong as ordinary nylon fiber. Picture by Casey H. Kyhl courtesy of US Navy.

These are some of Kevlar's properties:

It's strong but relatively light. The specific tensile strength (stretching or pulling strength) of both Kevlar 29 and Kevlar 49 is over eight times greater than that of steel wire.

Unlike most plastics it does not melt: it's reasonably good at withstanding temperatures and decomposes only at about 450°C (850°F).

Unlike its sister material, Nomex, Kevlar can be ignited but burning usually stops when the heat source is removed.

Very low temperatures have no effect on Kevlar: DuPont found "no embrittlement or degradation" down to −196°C (−320°F).

Like other plastics, long exposure to ultraviolet light (in sunlight, for example) causes discoloration and some degradation of the fibers in Kevlar.

Kevlar can resist attacks from many different chemicals, though long exposure to strong acids or bases will degrade it over time.

In DuPont's tests, Kevlar remained "virtually unchanged" after exposure to hot water for more than 200 days and its super-strong properties are "virtually unaffected" by moisture.

And what's bad?

It's worth noting that Kevlar also has its drawbacks. In particular, although it has very high tensile (pulling) strength, it has very poor compressive strength (resistance to squashing or squeezing). That's why Kevlar isn't used instead of steel as a primary building material in things like buildings, bridges, and other structures where compressive forces are common.

How is Kevlar made?

There are two main stages involved in making Kevlar. First you have to produce the basic plastic from which Kevlar is made (a chemical called poly-para-phenylene terephthalamide -no wonder they call it Kevlar). Second, you have to turn it into strong fibers. So the first step is all about chemistry; the second one is about turning your chemical product into a more useful, practical material.

Polyamides like Kevlar are polymers (huge molecules made of many identical parts joined together in long chains) made by repeating amides over and over again. Amides are simply chemical compounds in which part of an organic (carbon-based) acid replaces one of the hydrogen atoms in ammonia (NH3). So the basic way of making a polyamide is to take an ammonia-like chemical and react it with an organic acid. This is an example of what chemists call a condensation reaction because two substances fuse together into one.

Artwork: Kevlar's monomer: C=carbon, H=hydrogen, O=oyxgen, N=nitrogen, - is a single chemical bond, and = is a double bond. This basic building block is repeated over and over again in the very long chains that make up the Kevlar polymer. Source: "US Patent: 3287323: Process for the production of a highly orientable, crystallizable, filament" by Stephanie Kwolek et al.

Kevlar's chemical structure naturally makes it form in tiny straight rods that pack closely together, like lots of stiff new pencils stuffed tightly into a box (only without the box). These rods form extra bonds between one another (known as hydrogen bonds) giving extra strength-as though you'd glued the pencils together as well. This bonded rod structure is essentially what gives Kevlar its amazing properties. (More technically speaking, we can say the Kevlar rods are showing what's called nematic behavior (lining up in the same direction), which is also what happens in the liquid crystals used in LCDs (liquid crystal displays).)

You probably know that natural materials such as wool and cotton have to be spun into fibers before they can turned into useful textile products-and the same is true of artificial fibers such as nylon, Kevlar, and Nomex. The basic aramid is turned into fibers by a process called wet spinning, which involves forcing a hot, concentrated, and very viscous solution of poly-para-phenylene terephthalamide through a spinneret (a metal former a bit like a sieve) to make long, thin, strong, and stiff fibers that are wound onto drums. The fibers are then cut to length and woven into a tough mat to make the super-strong, super-stiff finished material we know as Kevlar.

Artwork: How Kevlar is made. 1) The rodlike Kevlar molecules start off in dilute solution. 2) Increasing the concentration increases the number of molecules but doesn't make them align. At this stage, the molecules are still tangled up and not extended into straight, parallel chains. 3) The wet-spinning process causes the rods to straighten out fully and align so they're all oriented in the same direction-forming what's called a nematic structure-and this is what gives Kevlar its exceptionally high strength. Image based on an original artwork from DuPont's Kevlar Technical Guide (see references below).

What's Kevlar used for?

Kevlar can be used by itself or as part of a composite material (one material combined with others) to give added strength. It's probably best known for its use in bulletproof vests and knifeproof body armor, but it has dozens of other applications as well. It's used as reinforcement in car tires, in car brakes, in the strings of archery bows, and in car, boat, and even aircraft bodies. It's even used in buildings and structures, although not (because of its relatively low compressive strength) as the primary structural material.

What makes Kevlar such a good antiballistic material?

Photo: Think of Kevlar as a lightweight modern alternative to heavy, cumbersome, medieval suits of armor! Photo by Staff Sgt. Nate Hauser courtesy of US Marine Corps.

If you've read our article on bullets, you'll know that they damage things-and people-because they travel at high speeds with huge amounts of kinetic energy. Although there's no such thing as completely "bulletproof," materials like bulletproof glass do a good job at protecting us by absorbing (soaking up) and dissipating (spreading out) the energy of a bullet.

Kevlar is an excellent antiballistic (bullet- and knife-resistant) material because it takes a great deal of energy to make a knife or a bullet pass through it. The tightly woven fibers of highly oriented (lined-up) polymer molecules are extremely hard to move apart: it takes energy to separate them. A bullet (or a knife pushed hard by an attacker) has its energy "stolen" from it as it tries to fight its way through. If it does manage to penetrate the material, it's considerably slowed down and does far less damage.

Although Kevlar is stronger than steel, it's about 5.5 times less dense (the density of Kevlar is about 1.44 grams per cubic centimeter, compared to steel, which is round about 7.8-8 grams per cubic centimeter). That means a certain volume of Kevlar will weigh 5-6 times less than the same volume of steel. Think back to medieval knights with their cumbersome suits of armor: in theory, modern Kevlar gives just as much protection-but it's light and flexible enough to wear for much longer periods.

More layers = more protection

Chart: You need a greater thickness of Kevlar body armor to stop higher-speed (velocity) bullets. In theory, the thicker the Kevlar, the shorter the distance a bullet should be able to pass through (the shorter the penetration depth); in practice, it's a little bit more complicated than that.

If you think of Kevlar "soaking up" the energy of a bullet, it's fairly obvious that a greater thickness of Kevlar-more layers of the material bonded together-will give more protection.

How much Kevlar do you need to stop a bullet? It depends on the Kevlar and it depends on the weight, type, and speed of the bullet. Kevlar comes in different weights-and bullets also come in different types and weights and travel at very different speeds, with different amounts of energy. The bigger the bullet and the faster it's travelling, the more kinetic energy it has, the further it will penetrate, and the more damage it will do. You need more layers of Kevlar to stop bigger, faster bullets than smaller, slower ones. Typically, bulletproof vests have at least 8-16 layers of Kevlar and often 32-48 layers or even more. Some vests combine Kevlar with other materials, while others use different materials instead of Kevlar, such as Spectra®.

Generally speaking, the more layers of heavier Kevlar you have, the more protective your "bulletproof" armor, but the heavier, bulkier, and hotter it will be to wear, and the more it will restrict your movement. You could cover yourself with a million layers of Kevlar, which might stop most everyday bullets, but it's hardly going to be practical. So there's a tradeoff to be made between protection and usability. And, where Kevlar's concerned, it's not always a matter of "thicker equals better": there's another qualification too. Bullets travel fast-a rifle bullet can be going 10 times faster than a race car-and they're designed to deform when they hit things so they do more damage. According to some recent ballistics research, the Kevlar in a bulletproof vest will affect this process, sometimes making a bullet travel further into a target than if no (or less) Kevlar were used. That's why you need a lot of Kevlar in effective bulletproof vests, both to allow for how it might alter the bullet and to soak up all the bullet's energy.

Kevlar isn't always enough

If you want to protect soldiers against high-velocity rifle bullets, you're going to need much thicker armor than if you simply want to protect police officers against handgun bullets, which have lower velocity and less kinetic energy. It's important to remember that no material is 100 percent bulletproof-and sometimes even Kevlar isn't enough.

You can see this clearly in the official US National Institute of Justice Body Armor Classification, which ranks bulletproof vests and other body protection (made of Kevlar and other materials) on a scale from I to IV for its ability to protect against bullets fired from weapons of different power. At the low end of the scale, type IIA armor has to protect against smaller handgun bullets (typically 9mm full metal jacketed bullets weighing 8.0g or 0.3 oz and fired at about 373 m/s or 834 mph); you need at least 16 layers of Kevlar for that. Higher up the scale, type IIIA armor has to resist more powerful handheld bullets (such as .44 Magnum bullets weighing 15.6 g or 0.6 oz and fired at 436 m/s or 975 mph); that needs twice as much Kelvar-at least 30 layers. It's important to note that even Kevlar has its limits. For protection against rifle bullets (ordinary ones or armor-piercing ones), which travel much faster (850-900 m/s or 1900-2000 mph) with considerably higher kinetic energy, Kevlar isn't enough: you need body armor made from steel or ceramic plates (classified as type III and IV).

Find out more

On this website

On other sites

Books

For older readers

Enough for One Lifetime: Wallace Carothers, Inventor of Nylon by Matthew Hermes. Chemical Heritage Foundation, 1996. A dry but nonetheless interesting biography of the inventor of nylon (a material very similar to Kevlar). It gives a good sense of how modern, revolutionary materials tend to be "corporate inventions" rather than the work of single inventors.

For younger readers

Articles

Popular science and news

Kevlar 'Wallpaper' Could Protect Soldiers From RPG Blasts by Jordan Golson. Wired, May 29, 2015. How sheets of Kevlar "wallpaper" could be used to protect buildings and structures.

Stephanie L. Kwolek, Inventor of Kevlar, Is Dead at 90 by Jeremy Pearce. The New York Times, June 20, 2014. A shortr obituary of the chemical pioneer.

Armor on the Field: The NFL's Headlong Race to Build the Unbreakable Linebacker by Sean Conboy. Wired, July 9, 2012. Could Kevlar padding help to protect sports competitors from serious injury?

DuPont wins $900m Kevlar spy case: The Guardian, 15 September 2011. Kevlar is an extremely valuable invention and, like other technological pioneers, DuPont has to fight big legal cases to protect its "intellectual property."

School uniforms made slash-proof: BBC News, 14 August 2007. Could Kevlar protect children against knife crime?

Tribute to Inventive Women: BBC News, 27 November 2003. A short article about women inventors, including Stephanie Kwolek.

Kevlar Enters Spotlight As New 'Miracle Fiber' by Gerd Wilcke. The New York Times, May 13, 1974. How the Times described the early development of Kevlar back in the 1970s.

Technical

Please do NOT copy our articles onto blogs and other websites

Articles from this website are registered at the US Copyright Office. Copying or otherwise using registered works without permission, removing this or other copyright notices, and/or infringing related rights could make you liable to severe civil or criminal penalties.

Text copyright © Chris Woodford 2008, 2020. All rights reserved. Full copyright notice and terms of use.

"Nomex", "Kevlar", and "DuPont" are trademarks or registered trademarks of E. I. Du Pont de Nemours and Company.

"Spectra" is a registered trademark of Honeywell International Inc.

More to explore on our website...

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How does Kevlar work? | Why is Kevlar so strong?

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by Chris Woodford. Last updated: February 25, 2020. Nature has given us some amazing materials. There's wood: a material so strong and versatile you can use it for everything from making paper to building houses. There's also wool, with insulation so effective it lets sheep stand outside in the snow all winter.

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Get access to files anywhere through secure cloud storage and file backup for your photos, videos, files and more with Google Drive.

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Cotton Versus Polyester

Not sure if you should buy a cotton or polyester shirt? Or perhaps a cotton/polyester blend? Although polyester has only been around for roughly half a century, it's use for fabric-based products continues to grow. On the other hand, cotton's popularity shows no signs of waning away anytime soon. Here's how these two wonder fabrics compare.

Cotton

Cotton fabric is highly regarded for its versatility and natural comfort. Harvested from the cotton plant, this soft, fluffy material is used for apparel, bedding, thread, tarpaulins, towels, and many other products. The cultivation and use of cotton dates back to prehistoric times.

Cotton has a softer, more supple feel than polyester and is less likely to irritate the skin. Cotton is also breathable which further contributes to its comfort. For those with sensitive skin, including infants, cotton is the better choice. When it comes to towels, washcloths, underwear, sheets, and pillowcases, cotton is king.

Polyester

Polyester is a petroleum-based synthetic fiber that was created in the 1940's by British and American chemists. In 1951, it was marketed by du Pont under the name Dacron. Today, polyester is used in the manufacture of many products including clothing, recording tapes, electrical insulation, carpeting, drapes, and miscellaneous other home furnishings.

Polyester and other synthetic fibers enable the creation of materials with superior water, wind and environmental resistance compared to cotton and other plant-derived fibers. When's the last time you saw a raincoat made from cotton?

Shrinkage, Durability, Wrinkling

Polyester is generally more durable than cotton and less prone to fading, shrinking and wrinkling. However, it is more subject to runs and pulls. For certain occupations, such as a restaurant worker, the durability of polyester is a clear advantage for clothing that is washed frequently and subjected to harsh detergents. Note that heavier weight cotton fabrics such as jeans are quite durable and can last a long time.

Poly/cotton blended products combine the softness of cotton with the durability of polyester. They tend to keep their shape and color, are not prone to wrinkling, and shrink very little, even when washed with warm or hot water. The cotton component also makes them more comfortable than products made solely of polyester. Blended products generally cost less and last longer than 100% cotton.

Other Properties

Polyester is less absorbent than cotton and hence it dries faster. Some polyester garments are designed to be moisture wicking, an attribute that is extremely useful for athletic pursuits and cold weather activities such as hunting.

Polyester's low absorbency also makes it more stain resistant than cotton. Furthermore, polyester does not require hot water when washed. This translates to energy savings over the lifetime of a polyester garment relative to a cotton garment.

Environmental Impact

Ecologically speaking, both cotton and polyester have their drawbacks, although polyester, which is made from petroleum, may have a slight edge. Cotton is the most pesticide-dependent crop in the world, using as many as one-fourth of all pesticides made. It is also a very water intensive crop. Both fabrics involve copious amounts of water, energy, and toxic chemicals during the manufacturing process.

Unlike polyester, cotton is biodegradable so old, discarded clothing will eventually break down into natural compounds. Cotton is also a renewable and sustainable resource, although there are environmental issues associated with the way it is commonly grown.

Fire Hazard

Cotton is more combustible than polyester. It ignites easily and burns rapidly, leaving behind a light ash residue. Polyester resists ignition but once ignited, it melts and causes severe localized burns. The fire hazard is also high with cotton/polyester blends due to the high rate of burning and fabric melting. The safest route is to purchase clothes that are treated with fire retardant materials.

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Not sure if you should buy a cotton or polyester shirt? Or perhaps a cotton/polyester blend? Although polyester has only been around for roughly half a century, it's use for fabric-based products continues to grow. On the other hand, cotton's popularity shows no signs of waning away anytime soon.

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Cotton vs. Polyester - the Pros and Cons

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Cotton vs. Polyester - the Pros and Cons

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Sewing Parts Online - Everything Sewing, Delivered Quickly To Your Door

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So, what's the big difference between cotton and polyester fabric? There are those who swear by cotton, but cheaper polyester is pretty tempting, isn't it? You may think that the lower cost of polyester means a lower quality product, but that isn't necessarily the case.

Polyester is great for some projects, while cotton is great for others. The real trick is to weigh the pros and cons to decide which is the right choice for you. Some people only want to work with 100% cotton because it's so easy to sew and is predictable. You know exactly what you're getting. Others prefer polyester because it's long-lasting and usually less expensive.

Let's go over each.

Breathable: This natural fiber lets your skin breathe. It also absorbs moisture to keep your body temperature stable.

Soft, but strong: The fibers are less abrasive than polyester, so it feels super soft on your skin. That being said, some cotton fabric is designed to be strong and rough, like heavy duty cotton canvas. It all depends on the weave and the finish.

Great for sensitive skin: Because it is so much softer, those with sensitive skin tolerate 100% cotton better than polyester. With organic products becoming increasingly popular, you can find cotton fabric made with very little chemical processing.

Easy to dye: The fibers hold dye incredibly well. It also tends to dye evenly and produce a truer, deeper color. However, with excessive exposure to sunlight and time (decades), the dye will eventually fade. Also, cotton will shrink with the first washing and drying.

Biodegradable: Cotton will break down over time. Cotton isn't as durable as polyester in the long run. However, proper care can prolong the life of cotton. Try to avoid prolonged exposure to excessive sunlight and moisture.

Polyester

Long lasting: Polyester is a man-made fiber. It's very resilient and can withstand a good deal of wear and tear. It's basically plastic. In fact, plastic bottles can be recycled into polyester fabric. Polyester is not compostable, meaning it doesn't break down well in soil. Think about this in a landfill.

Less fading: Polyester holds dye well to prevent fading, but doesn't produce as "rich" of a color as cotton. High-quality polyester holds its shape well and doesn't shrink.

Dries quickly: Unlike cotton, polyester isn't absorbent. It's definitely not your go-to for towels. However, it dries super fast. So if you want to reduce that electricity bill, you might want to sew polyester clothing.

Less wrinkling: It's more resistant to wrinkles than cotton. This is great for anyone who dreads ironing.

Nonbreathing: Polyester doesn't let your skin breathe like cotton. For instance, if you wear a polyester shirt in the summer, you might find yourself pretty sweaty. That being said, there are many performance wear polyester products specifically engineered to wick sweat away from your body, but it really only works if the fabric is skin tight. If you buy a low-quality product, you'll notice a weird after smell.

Cotton/Poly Mix

This is the best of both worlds. Developers take the best qualities of both and weave them together to make one heck of a fabric. This stuff is great for apparel and home decor.

Quilters will still tell you to stick to 100% cotton and they have good reasons to say that. It's easy to use, it's predictable, and it shrinks at the same rate.

I say experiment with as much fabric as you can and see what you like best. It's all about the individual sewist and how you like to sew.
What about the environment?
This can make or break it for some people. Many people prefer cotton because it is a plant-based product and is "sustainable". Now, take a look at the two photos below.

Pretty similar, right? The first image is a cotton factory and the second image is a polyester factory. Either way, both fabrics are created in power-sucking factories. Both go through multiple chemical processes to make the final product and both products will be shipped around the globe. Even when you consider that polyester can be made from recycled plastic bottles, check out the huge process it goes through.

Now, consider all of the chemicals pumped into the atmosphere and all of the energy used to power the plants.
Before you start hating polyester, just know cotton has a dirty side, too. Cotton farming uses the most pesticides of any crop in the world. Every time it rains or the plant decomposes, chemicals leak into the ground water and surrounding water sources. Cotton takes a ton of land to grow and that land has to be watered a lot! Then, it all needs to be harvested using motorized farming equipment. Unless those tractors run on solar power, they aren't great for the environment.

Do you want to really be eco-friendly? Up-cycle and sew every scrap. Use your sewing skills to fix your clothing and home goods instead of buying new.

You could also start your own organic cotton fields. You could hand pick and process the cotton, then weave your own fabric. I guess that would be the most eco-friendly.

Personally, I'm sticking with fabric off the bolt.

Hey, I recycle. Don't judge.

References:
Frey, M., Li, L., & Browning, K. (n.d.). Retrieved from here
Baugh, G. (n.d.). Retrieved from here

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The 411 on Cotton vs. Polyester: The Pros and Cons

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So, what's the big difference between cotton and polyester fabric? There are those who swear by cotton, but cheaper polyester is pretty tempting, isn't it? You may think that the lower cost of polyester means a lower quality product, but that isn't necessarily the case.

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Polyester Fabric - WWII and the Invention of Polyester - Quatr.us

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Polyester Fabric - WWII and the Invention of Polyester - Quatr.us

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Who invented polyester fabric?

The British scientists John Whinfield and James Dickson first invented polyester cloth in 1941 in England. World War II had made it hard to get cotton, and British people needed clothes to wear! After World War II was over, in 1945, the United States company DuPont bought the right to make polyester. By 1950 a factory in Delaware was actually making polyester fabric.

What is polyester made of?

People make polyester out of oil. You take the oil, which is a kind of very big hydrocarbon molecule, and break it down into two smaller molecules, ethylene glycol and dimethyl naphthalate. Both of these molecules are still made entirely of oxygen, carbon, and hydrogen atoms. Dimethyl terephthalate is an ester, and ethylene glycol is a kind of alcohol. When you mix the ester and the alcohol together, they form molecules with both positive and negative charges. The charges force the molecules to line up in chains of crystals that hold together as long fibers.

Recycling plastic bottles into polyester fabric

This polymerized material comes out of the machine in long ribbons, and you cut the ribbons into little chips and let them harden. Then you melt the chips again and push the goo out through little holes to make thinner ribbons, and wind the thinner ribbons around spools.

Then you heat the thinner ribbons and stretch them out to about five times their original length, to make them thin enough to use as thread to weave cloth. This seems complicated but it's actually less work than growing cotton and picking it and then spinning the cotton into thread.

Since the 1960s, polyester has been the cheapest kind of cloth. Almost half of all the world's clothing is made of polyester. You are probably familiar with polyester fabric mainly from team shirts like for soccer or basketball.

Because we make polyester out of oil, polyester clothing will get more expensive as we run out of oil and oil gets more expensive.

Did you find out what you wanted to know about polyester fabric? Got more questions? Let us know in the comments!

Learn by doing: find some polyester clothing (in a store or your closet) and check it out.

Bibliography and further reading about polyester fabric:

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Polyester fabric - World War II and the invention of polyester

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Polyester fabric goes back to the Second World War, when two British scientists figured out how to make a new, cheap kind of cloth out of oil. Polyester is easier to make than cotton or linen, so people can get clothes cheaper.

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Why is Cotton More Absorbent Than Nylon? - How Stuff Works

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Why is Cotton More Absorbent Than Nylon? - How Stuff Works

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The answer lies in the basic but remarkable molecular structure of cotton, nylon and water. The simple water molecule, with its one oxygen atom attached to two hydrogen atoms, causes a different action when it comes in contact with the complex molecules that make up cotton and nylon.

Water has a sticky quality that comes from its molecular structure. The oxygen atom attracts electrons, giving it a slightly negative charge. The two hydrogen atoms have a slightly positive charge. The positive and negative ends make the water molecule like a magnet ( dipole), which keeps water molecules together and makes the surface of a water drop slightly elastic. It also means that water molecules will bond easily with molecules with an opposite charge that come nearby.

Cotton and nylon are both made up of giant polymer molecules. Polymer molecules are often long chains of atoms linked in repeating patterns. There are a lot of atoms bonded to one another in these molecules, giving a lot of places where sticky water molecules can find a place to bond.

Cotton is pure cellulose, a naturally occurring polymer. Cellulose is a carbohydrate, and the molecule is a long chain of glucose (sugar) molecules. If you look at the structure of a cellulose molecule you can see the OH groups that are on the outer edge. These negatively charged groups attract water molecules and make cellulose and cotton absorb water well. Cotton can absorb about 25 times its weight in water. Chemists refer to substances like cotton as hydrophilic, which means that they attract water molecules.

Nylon is a synthetic material, meaning that chemists create the polymer molecules that make up nylon. More than 100 repeating units of carbon, oxygen, hydrogen and nitrogen atoms make up the long chain nylon molecule. The strength of the long nylon molecule made it a great replacement for silk, which had a similar feel and texture.

The nylon molecule, too, has a great number of places where it can form bonds with water molecules, but not as many places as the cotton molecule. Nylon absorbs water, but not nearly as much as cotton. It only absorbs about 10 percent of its weight in water.

There are a couple of other things about cotton towels and nylon jackets that help them do what they are supposed to. Terrycloth, the fabric in towels, has lots of loops on its surface. That gives more places for the cotton and water to come into contact. Textile makers add resins and other water-repellant chemicals to nylon so that the water drops will run off rather than be absorbed.

Here are some interesting links:

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Why is cotton more absorbent than nylon?

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Towels are always made of cotton, and they work really well at absorbing water. On the other hand, water-repellant jackets are made of nylon, and they work pretty well at keeping you dry. Why is cotton more absorbent than nylon?

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Background

For centuries humankind has relied upon various plants and animals to provide the raw materials for fabrics and clothing. Silkworms, sheep, beaver, buffalo deer, and even palm leaves are just some of the natural resources that have been used to meet these needs. However, in the last century scientists have turned to chemistry and technology to create and enhance many of the fabrics we now take for granted.

There are two main categories of man-made fibers: those that are made from natural products (cellulosic fibers) and those that are synthesized solely from chemical compounds (noncellulosic polymer fibers). Rayon is a natural-based material that is made from the cellulose of wood pulp or cotton. This natural base gives it many of the characteristics-low cost, diversity, and comfort-that have led to its popularity and success. Today, rayon is considered to be one of the most versatile and economical man-made fibers available. It has been called "the laboratory's first gift to the loom."

In the 1860s the French silk industry was being threatened by a disease affecting the silkworm. Louis Pasteur and Count Hilaire de Chardonnet were studying this problem with the hope of saving this vital industry. During this crisis, Chardonnet became interested in finding a way to produce artificial silk. In 1885 he patented the first successful process to make a useable fiber from cellulose. Even though other scientists have subsequently developed more cost-effective ways of making artificial silk, Chardonnet is still considered to be the father of rayon.

For the next forty years this material was called artificial or imitation silk. By 1925 it had developed into an industry unto itself and was given the name by the Federal Trade Commission (FTC). The term at this time included any man-made fiber made from cellulose. In 1952, however, the FTC divided rayons into two categories: those fibers consisting of pure cellulose (rayon) and those consisting of a cellulose compound (acetate).

By the 1950s, most of the rayon produced was being used in industrial and home furnishing products rather than in apparel, because regular rayon (also called viscose rayon) fibers were too weak compared to other fibers to be used in apparel. Then, in 1955, manufacturers began to produce a new type of rayon-high-wet-modulus (HWM) rayon-which was somewhat stronger and which could be used successfully in sheets, towels, and apparel. The advent of HWM rayon (also called modified rayon) is considered the most important development in rayon production since its invention in the 1880s.

Today rayon is one of the most widely used fabrics in our society. It is made in countries around the world. It can be blended with natural or man-made fabrics, treated with enhancements, and even engineered to perform a variety of functions.

Raw Materials

Regardless of the design or manufacturing process, the basic raw material for making rayon is cellulose. The major sources for natural cellulose are wood pulp-usually from pine, spruce, or hemlock trees-and

cotton linters. Cotton linters are residue fibers which cling to cotton seed after the ginning process.

Strictly defined, rayon is a manufactured fiber composed of regenerated cellulose. The legal definition also includes manufactured fibers in which substitutes have not replaced more than 15 percent of the hydrogens.

While the basic manufacturing process for all rayon is similar, this fabric can be engineered to perform a wide range of functions. Various factors in the manufacturing process can be altered to produce an array of designs. Differences in the raw material, the processing chemicals, fiber diameter, post treatments and blend ratios can be manipulated to produce a fiber that is customized for a specific application.

Regular or viscose rayon is the most prevalent, versatile and successful type of rayon. It can be blended with man-made or natural fibers and made into fabrics of varying weight and texture. It is also highly absorbent, economical and comfortable to wear.

Regular viscose rayon does have some disadvantages. It's not as strong as many of the newer fabrics, nor is it as strong as natural cotton or flax. This inherent weakness is exacerbated when it becomes wet or overexposed to light. Also, regular rayon has a tendency to shrink when washed. Mildew, acid and high temperatures such as ironing can also result in damage. Fortunately, these disadvantages can be countered by chemical treatments and the blending of rayon with other fibers of offsetting characteristics.

High-wet-modulus rayon is a stronger fiber than regular rayon, and in fact is more similar in performance to cotton than to regular rayon. It has better elastic recovery than regular rayon, and fabrics containing it are easier to care for-they can be machine-washed, whereas fabrics containing regular rayon generally have to be dry-cleaned.

The Manufacturing
Process

While there are many variations in the manufacturing process that exploit the versatility of the fiber, the following is a description of the procedure that is used in making regular or viscose rayon.

Regardless of whether wood pulp or cotton linters are used, the basic raw material for making rayon must be processed in order to extract and purify the cellulose. The resulting sheets of white, purified cellulose are then treated to form regenerated cellulose filaments. In turn, these filaments are spun into yarns and eventually made into the desired fabric.

Processing purified cellulose

1 Sheets of purified cellulose are steeped in sodium hydroxide (caustic soda), which produces sheets of alkali cellulose. These sheets are dried, shredded into crumbs, and then aged in metal containers for 2 to 3 days. The temperature and humidity in the metal containers are carefully controlled.

2 After ageing, the crumbs are combined and churned with liquid carbon disulfide, which turns the mix into orange-colored crumbs known as sodium cellulose xanthate. The cellulose xanthate is bathed in caustic soda, resulting in a viscose solution that looks and feels much like honey. Any dyes or delusterants in the design are then added. The syrupy solution is filtered for impurities and stored in vats to age, this time between 4 and 5 days.

Producing filaments

3 The viscose solution is next turned into strings of fibers. This is done by forcing the liquid through a spinneret, which works like a shower-head, into an acid bath. If staple fiber is to be produced, a large spinneret with large holes is used. If filament fiber is being produced, then a spinneret with smaller holes is used. In the acid bath, the acid coagulates and solidifies the filaments, now known as regenerated cellulose filaments.

Spinning

4 After being bathed in acid, the filaments are ready to be spun into yarn. Depending on the type of yarn desired, several spinning methods can be used, including Pot Spinning, Spool Spinning, and Continuous Spinning. In Pot Spinning, the filaments are first stretched under controlled tension onto a series of offsetting rollers called godet wheels. This stretching reduces the diameter of the filaments and makes them more uniform in size, and it also gives the filaments more strength. The filaments are then put into a rapidly spinning cylinder called a Topham Box, resulting in a cake-like strings that stick to the sides of the Topham Box. The strings are then washed, bleached, rinsed, dried, and wound on cones or spools.
Spool Spinning is very similar to Pot Spinning. The filaments are passed through rollers and wound on spools, where they are washed, bleached, rinsed, dried, and wound again on spools or cones.

In Continuous Spinning, the filaments are washed, bleached, dried, twisted, and wound at the same time that they are stretched over godet wheels.

5 Once the fibers are sufficiently cured, they are ready for post-treatment chemicals and the various weaving processes necessary to produce the fabric. The resulting fabric can then be given any of a number of finishing treatments. These include calendaring, to control smoothness; fire resistance; pre-shrinking; water resistance; and wrinkle resistance.

High-Wet-Modulus Rayon
Manufacture

The process for manufacturing high-wet-modulus rayon is similar to that used for making regular rayon, with a few exceptions. First, in step #1 above, when the purified cellulose sheets are bathed in a caustic soda solution,

a weaker caustic soda is used when making HWM rayon. Second, neither the alkali crumbs (#1 above) nor the viscose solution (step #2) is aged in the HWM process. Third, when making HWM rayon, the filaments are stretched to a greater degree than when making regular rayon.

Quality Control

As with most chemically oriented processes, quality control is crucial to the successful manufacture of rayon. Chemical make-up, timing and temperature are essential factors that must be monitored and controlled in order to produce the desired result.

The percentages of the various fibers used in a blended fabric must be controlled to stay within in the legal bounds of the Textile Fiber Identification Act. This act legally defines seventeen groups of man-made fibers. Six of these seventeen groups are made from natural material. They include rayon, acetate, glass fiber, metallics, rubber, and azion. The remaining eleven fabrics are synthesized solely from chemical compounds. They are nylon, polyester, acrylic, modacrylic, olefin, spandex, anidex, saran, vinal, vinyon, and nytril.

Within each generic group there are brand names for fibers which are produced by different manufacturers. Private companies often seek patents on unique features and, as could be expected, attempt to maintain legal control over their competition.

Byproducts

As one of the industry's major problems, the chemical by-products of rayon have received much attention in these environmentally conscious times. The most popular method of production, the viscose method, generates undesirable water and air emissions. Of particular concern is the emission of zinc and hydrogen sulfide.

At present, producers are trying a number of techniques to reduce pollution. Some of the techniques being used are the recovery of zinc by ion-exchange, crystallization, and the use of a more purified cellulose. Also, the use of absorption and chemical scrubbing is proving to be helpful in reducing undesirable emissions of gas.

The Future

The future of rayon is bright. Not only is there a growing demand for rayon worldwide, but there are many new technologies that promise to make rayon even better and cheaper.

For a while in the 1970s there was a trend in the clothing industry toward purely synthetic materials like polyester. However, since purely synthetic material does not "breath" like natural material, these products were not well received by the consumer. Today there is a strong trend toward blended fabrics. Blends offer the best of both worlds.

With the present body of knowledge about the structure and chemical reactivity of cellulose, some scientist believe it may soon be possible to produce the cellulose molecule directly from sunlight, water and carbon dioxide. If this technique proves to be cost effective, such hydroponic factories could represent a giant step forward in the quest to provide the raw materials necessary to meet the world wide demand for man-made fabric.

Where To Learn More

Books

Corbman, Bernard P. Textiles: Fiber to Fabric, 6th ed. McGraw-Hill, 1983.

Hollen, Norma, Jane Saddler, Anna Langford, and Sara Kadolph. Textiles, 6th ed. Macmillan, 1988.

Periodicals

Foley, Theresa M. "Rayon Fiber Manufacturer Shuts Down, Threatening U.S. Booster Production." Aviation Week & Space Technology. November 7, 1988, p. 29.

Smith, Emily T. "A Safe Shortcut around the Toxic Road to Rayon." Business Week. February 11, 1991, p. 80.

Templeton, Fleur. "From Log to Lingerie in a Few Easy Steps." Business Week. April 6, 1992, p. 95.

"Turning Corn and Paper into Rayon." USA Today. June, 1991, p. 7.

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How rayon is made - material, manufacture, making, used, processing, structure, procedure, steps

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For centuries humankind has relied upon various plants and animals to provide the raw materials for fabrics and clothing. Silkworms, sheep, beaver, buffalo deer, and even palm leaves are just some of the natural resources that have been used to meet these needs.

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How 75 Years Ago Nylon Stockings Changed the World - Smithsonian Magazine

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How 75 Years Ago Nylon Stockings Changed the World - Smithsonian Magazine

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The quest to replace natural silk led to the very first fully synthetic fiber and revolutionized the products we depend on

smithsonianmag.com

Major technological innovations such as gunpowder, GPS and freeze dried ice cream are more likely to be credited to military research than to women's undergarments, but one humble pair of lady's stockings in the Smithsonian collections represents nothing less than the dawn of a new age-the age of synthetics.

Woven of a completely new material, the experimental stockings held in the collections of the National Museum of American History were made in 1937 to test the viability of the first man made fiber developed entirely in a laboratory. Nylon was touted as having the strength of steel and the sheerness of cobwebs. Not that women were jonesing for the feel of steel or cobwebs around their legs, but the properties of nylon promised a replacement for the luxurious, but oh so delicate silk that was prone to snag and run.

An essential part of every woman's wardrobe, stockings provided the perfect vehicle for DuPont, the company responsible for the invention of nylon, to introduce their new product with glamorous aplomb. Nylon stockings made their grand debut in a splashy display at the 1939 World's Fair in New York. By the time the stockings were released for sale to the public on May 15, 1940 demand was so high that women flocked to stores by the thousands. Four million pairs sold out in four days.

In her book Nylon; The Story of a Fashion Revolution, Susannah Handley writes: "Nylon became a household word in less than a year and in all the history of textiles, no other product has enjoyed the immediate, overwhelming public acceptance of DuPont nylon."

The name may have become synonymous with stockings, but hosiery was merely the market of choice for nylon's introduction. According the American Chemical Society it was a well calculated decision. They state on their web site:

The decision to focus on hosiery was crucial. It was a limited, premium market. "When you want to develop a new fiber for fabrics you need thousands of pounds," said Crawford Greenewalt, a research supervisor during nylon development who later became company president and CEO. "All we needed to make was a few grams at a time, enough to knit one stocking."

The experimental stockings were manufactured by Union Hosiery Company for Dupont with a cotton seam and a silk welt and toe. They were black because scientists hadn't yet figured out how to get the material to take flesh-colored dye. One of the other hurdles to be overcome was the fact that nylon distorted when exposed to heat. Developers eventually learned to use that property to their advantage by stretching newly sewn stockings over leg-shaped forms and steaming them. The result was silky smooth, form-fitting hosiery that never needed ironing.

Nylon's impact on fashion was immediate, but the revolution sparked by the invention of what was originally called fiber-66 rapidly extended its tendrils down through every facet of society. It has given rise to a world of plastics that renders our lives nearly unrecognizable from civilizations of a century ago.

"It had a huge impact," says Matt Hermes, associate professor at the bioengineering department at Clemson University. He is a former chemist for DuPont who worked with some of the early developers of synthetics and wrote a biography on nylon's inventor Wallace Caruthers. "There's a whole series of synthetic materials that indeed came from the base idea that chemists can design and develop a series of materials that had certain properties, and the ability to do it from the most basic molecules."

There-in lies the true revolution of nylon. Synthetic materials were not completely new. But until the breakthrough of nylon, no useful fibers had ever been synthesized entirely in the laboratory. Semi-synthetics such as Rayon and cellophane were derived from a chemical process that required wood pulp as a basic element. Manufacturers were stuck with the natural properties plant material brought to the table. Rayon for instance was too stiff, ill-fitting and shiny to be embraced as a replacement for real silk, which is, of course, merely the chemical processing of wood pulp in the belly of a silk worm rather than a test tube. Nylon, on the other hand, not only made great stockings, but was manufactured through human manipulation of nothing more than "coal, air and water"-a mantra often repeated by its promoters.

The process, involves heating a specific solution of carbon, oxygen, nitrogen and hydrogen molecules to very high temperature until the molecules begin to hook together in what's called a long-chain polymer that can be drawn from a beaker on the tip of a stir stick like a string of pearls.

The completely unnatural features of nylon may not play as well in the marketplace today, but in 1940, on the heels of the Great Depression, the ability to dominate the elements through chemistry energized a nation weary of economic and agricultural uncertainty. "One of the largest impacts was not only the generation of the synthetic material era," says Hermes, "but also the idea that the nation could recover from the economic doldrums that went on year after year during the depression. When new materials began to surface, these were hopeful signs."

It was a time when industrial chemistry promised to lead humankind into a brighter future. "All around us are the products of modern chemistry," boasted one promotional film from 1941. "Window shades, draperies, upholstery and furniture, all are made of, or covered with, something that came from a test-tube. . . in this new world of industrial chemistry the horizon is unlimited."

The modern miracle of that first pair of nylon stockings represented the epitome of human superiority over nature, American ingenuity and a luxurious lifestyle. Perhaps more important, however is that the new material being woven into hosiery promised to release the nation from reliance on Japan for 90 percent of its silk at a time when animosity was reaching a boiling point. In the late 1930s, the U.S. imported four-fifths of the world's silk. Of that, 75 to 80 percent went into the making of women's stockings-a $400,000 annual industry (about $6 million in today's dollars). The invention of nylon promised to turn the tables.

By 1942, the significance of that promise was felt in force with the outbreak of World War II. The new and improved stockings women had quickly taken to were wrenched away as nylon was diverted to the making of parachutes (previously made of silk). Nylon was eventually used to make glider tow ropes, aircraft fuel tanks, flak jackets, shoelaces, mosquito netting and hammocks. It was essential to the war effort, and it has been called "the fiber that won the war."

Suddenly, the only stockings available were those sold before the war or bought on the black market. Women took to wearing " leg make-up" and painting seams down the backs of their legs to give the appearance of wearing proper stockings. According to the Chemical Heritage Foundation, one entrepreneur made $100,000 off of stockings produced from a diverted nylon shipment.

After the war the re-introduction of nylon stockings unleashed consumer madness that would make the Tickle-Me-Elmo craze of the 90s look tame by comparison. During the "nylon riots" of 1945 and '46 women stood in mile-long lines in hopes of snagging a single pair. In her book Handley writes: "On the occasion when 40,000 people queued up to compete for 13,000 pairs of stockings, the Pittsburgh newspaper reported 'a good old fashioned hair-pulling, face-scratching fight broke out in the line.'"

Nylon stockings remained the standard in women's hosiery until 1959 when version 2.0 hit the shelves. Pantyhose-panties and stockings all in one-did away with cumbersome garter belts and allowed the transition to ever higher hemlines. But by the 1980s the glam was wearing off. By the 90s, women looking for comfort and freedom began to go au-natural, leaving their legs bare as often as not. In 2006, the New York Times referred to the hosiery industry as "An Industry that Lost its Footing."

In the last 30 years sheer pantyhose have done a complete 180, devolving into fashion no-no's except for sheer black and in offices where dress code prohibits bare legs. The mere mention of pantyhose ruffles some women's feathers. In 2011, Forbes writer Meghan Casserly blogged they were "oppressive," "sexist," "tacky" and "just plain ugly." She was striking out against one pantyhose manufacturer's campaign to re-invigorate the market among younger women.

Fashion editor for the Washington Post, Robin Givhan takes a more subdued stance. "I wouldn't say they're tacky. They're just not a part of the conversation; they're a non-issue in fashion."

Even at formal affairs, Givhan says bare legs are now the norm. "I think there's a certain generation of women that feel they're not properly dressed in a polished way unless they're wearing them, but I think they're going the way of the dodo bird," she says. "I don't think there is even the slightest chance that they're coming back."

No matter, they've made their point. Nylon has become an indispensible part of our lives found in everything from luggage and furniture to computers and engine parts. Chemistry and human ambition have transformed the world in which we live.

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How 75 Years Ago Nylon Stockings Changed the World

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smithsonianmag.com Major technological innovations such as gunpowder, GPS and freeze dried ice cream are more likely to be credited to military research than to women's undergarments, but one humble pair of lady's stockings in the Smithsonian collections represents nothing less than the dawn of a new age-the age of synthetics.

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by Chris Woodford. Last updated: January 31, 2019.

If wood is the world's most versatile natural material, nylon is probably the most useful synthetic one. It's a plastic that can be molded into everyday products or drawn into fibers for making fabrics-and its launch in the late 1930s truly changed the world. Don't believe me? Let me explain. You can pretty much live your entire life with nylon by your side. You can snooze away on brushed nylon sheets until your alarm clock (powered by nylon gears) wakes you up. Hop across the nylon rug or carpet to your kitchen, maybe eat your breakfast from a nylon bowl, before cleaning your teeth with a nylon toothbrush. Hold a nylon umbrella over your head to keep out the rain when you set out for work or school or, if the sun's shining and you're heading to the beach, wear your quick-drying nylon swimming shorts instead. Feeling adventurous? You could try jumping from an airplane and have a nylon parachute bring you safely to the ground! Those are just a few of the things that nylon does for us every single day. What makes this material so amazing? Let's take a closer look!

Photo: Left: The world was introduced to nylon in 1938 when the DuPont chemical company used the material to make synthetic toothbrushes. Right: You can make nylon bristles pretty much any length. This amazing citrus fruit harvesting machine has nylon filaments that are about 3.5m (~12ft) long. They spin around and shake the fruit gently from the trees. Photo by Keith Weller courtesy of US Department of Agriculture/Agricultural Research Service (USDA/ARS).

The science of nylon

Nylon is a polymer-a plastic with super-long, heavy molecules built up of short, endlessly repeating sections of atoms, just like a heavy metal chain is made of ever-repeating links. Nylon is not actually one, single substance but the name given to a whole family of very similar materials called polyamides. So whenever we say "nylon is..." it's generally more correct to say "nylons are..."

One reason there's a family of nylons is because the original and most common form of the material, nylon 6,6, was patented by E.I. du Pont de Nemours & Company (DuPont™), the US firm where it was invented, so rivals such as German chemical giant BASF had to come up with alternatives. Another reason is that the different kinds of nylon have different properties, which makes them useful for different things. Other kinds of nylon include nylon 6, nylon 6,12, and nylon 5,10. Two other "fantastic plastics" made by DuPont, Kevlar® (a superstrong material used in bulletproof vests) and Nomex ® (a fireproof textile used in racing car suits and oven gloves), are also polyamides and they're chemically related to nylon.

Photo: Nylon couldn't wait to became a space-age material. In 1952, NASA rocket scientist Wernher von Braun proposed building a space station out of flexible nylon, which could be carried into space by a relatively small rocket and then inflated like a car tire. That concept never made it off the ground, but nylon still played its part in space history: the flag planted on the Moon by Neil Armstrong in 1969 was made from-guess what-nylon! Illustration by Chesley Bonestell courtesy of NASA Marshall Space Flight Center (NASA-MSFC).

Manufacture

Unlike traditional materials such as wood, iron, wool, and cotton, nylon does not exist in nature: we have to make it in chemical plants from organic (carbon-based) chemicals found in natural materials such as coal or petroleum. (It's also possible to make nylon from renewable materials; Zytel®, a type of nylon produced by DuPont, comes from castor oil-so, essentially, vegetables.) The nylon polymer is made by reacting together two fairly large molecules using moderate heat (roughly 285°C or 545°F) and pressure in a reaction vessel called an autoclave, which is a bit like an industrial-strength kettle. One of the starting molecules is called hexane-1,6-dicarboxylic acid (also called adipic acid) and the other is known as 1,6-diaminohexane (also called hexamethylenediamine). When they combine, they fuse together to make an even larger molecule and give off water in a chemical reaction known as condensation polymerization (condensation because water is eliminated; polymerization because a big, repeating molecule is produced). The large polymer formed in this case is the most common type of nylon-known as nylon-6,6 because the two molecules from which it's made each contain six carbon atoms; other nylons are made by reacting different starting chemicals. Usually this chemical process produces a giant sheet or ribbon of nylon that is shredded into chips, which become the raw material for all kinds of everyday plastic products.

Artwork: How nylon 6,6 is made by condensation polymerization. 1) The two ingredients are 1,6-diaminohexane (left, red) and hexane-1,6-dicarboxylic acid (right, black). 2) A hydrogen (H) from the (red) diaminohexane joins with a hydroxide (OH) from the (black) acid. 3) A water molecule (blue) is lost (which is why the process is called condensation) as the two molecules join together. 4) The same thing happens over and over again, making a bigger and bigger molecule from the same repeated components-the process we call polymerization.

Nylon clothes and similar products are made not from chips but from fibers of nylon, which are effectively strands of plastic yarn. They're made by melting nylon chips and drawing them through a spinneret, which is a wheel or plate with lots of tiny holes in it. Fibers of different length and thickness are made by using holes of different size and drawing them out at different speeds. Strands are sometimes used by themselves (for example, in the manufacture of stockings) and sometimes tens, hundreds, or even thousands are wrapped together to make thicker and stronger yarns (similar to cotton but far stronger).

Photo: Strong and lightweight: clothes aren't the only things made from nylon fabrics. Parachutes were originally made from silk; now they're more likely to be made from "ripstop" nylons. Photo by Senior Airman Micky Bazaldua courtesy of US Air Force.

Photo: A closeup of the criss-cross reinforcement in ripstop nylon. These little rectangles are designed to stop rips or punctures from spreading, so a tiny tear won't get bigger by racing through the whole material.

In everyday speak, we "measure" the strength of nylon yarn in units called deniers, which is the weight in grams of 9000 meters of the yarn; that's loosely true because thicker and heavier materials are stronger than finer ones. You might have seen stockings for sale marked as "15 denier" without ever really understanding what that means. Roughly speaking, it's an indication of how thick (and therefore how strong) the nylon fabric is, but it's actually a measurement of the weight of the nylon fibers from which it's made. If you see stockings described as 40-denier, it means a 9-km (roughly 6-mile) roll of the yarn they're made from would weigh just 40 grams (1.4 oz)-which gives you some idea just how fine nylon yarn really is! Tights and stockings with higher denier measurements are thicker and stronger; ones with lower denier measurements are more sheer and more fragile. Ultra-sheer tights, for example, are usually less than 10 denier; thick winter tights can be 100 denier or more. However, it's very important to note that scientists are much stricter about all this: the denier isn't a measurement of strength at all. For that, we need to use carefully defined units, such as grams (force) per denier, technically referred to as the tenacity (effectively the breaking strength of a fiber and equivalent to measurements like kilograms per square centimeter or pounds per square inch for conventional materials).

Properties of nylon

Generally, nylon is a silky smooth thermoplastic (which means it melts and turns runny when you heat it up, generally at around 260°C or 500°F) that's strong, tough, and durable (it's reasonably wear-proof and resists sunlight and weathering). Since it's a synthetic plastic, it's highly resistant to attack from such natural nasties as molds, insects, and fungi. It's waterproof (hence its use in umbrellas and waterproof clothes) and fast-drying because (unlike with natural fabrics like cotton or wool) water molecules can't easily penetrate the outer surface. Although reasonably resistant to quite a lot of everyday substances, nylon will dissolve in phenol, acids, and some other harsh chemicals.

Uses of nylon

It's almost easier to say what nylon isn't used for. Look around your home and you'll find it's packed with nylon. The first products made with this amazingly versatile chemical were toothbrushes and women's stockings. Later it was used in everything from tennis rackets and parachutes to inexpensive machine gears, fishing lines, and nylon rugs. Some cars even have body parts made from nylon!

Who invented nylon?

Photo: Chemical laboratory courtesy of NASA Glenn Research Center (NASA-GRC).

Everyone's heard of nylon, but hardly anyone outside the world of chemistry knows the name of Wallace Carothers (1896-1937), its brilliant, enigmatic, and ultimately tragic inventor. Carothers was a promising academic chemist working at Harvard University when DuPont™ lured him to its Wilmington, Delaware headquarters in the late 1920s. His job was leading a research team that was experimenting with polymerization and he scored an early success with the invention of neoprene, a synthetic rubber now best known for its use in wetsuits.

Photos The front page of Wallace Carothers' patent for nylon ( US Patent 2,071,250: "Linear condensation polymers" courtesy of US Patent and Trademark Office).

In spring 1930, one of the Carothers team, Julian Hill, accidentally produced a strange gooey blob of material that he could draw out into long, thin fibers. After further research and development, this material became nylon 6,6-the world's first commercially successful synthetic polymer-and DuPont patented it a few years later. This should have been a triumph for Carothers, but he'd been plagued by alcoholism and depression for some time and personal problems had ground him down. Tragically, he found life unbearable and committed suicide in a Philadelphia hotel in 1937.

The year after his death, DuPont launched nylon commercially, initially in plastic toothbrushes. Two years later, in 1940, the new material caused an incredible sensation when the first nylon stockings went on sale-something like 5 million pairs were sold on the first day alone!

In his nine years at DuPont, Wallace Carothers filed over 50 patents, but doubt about the value of his work was one of several factors that had apparently driven him to his death. If only he'd known how important his work was about to become. Today, he is rightly regarded as a pioneer of synthetic materials and considered one of the most important chemists of modern times.

Find out more

On this website

On other websites

Fibers and Fabrics: A guide for students and teachers that describes the world of modern textile science, from the UK's National STEM Centre.

Wallace Hume Carothers andWallace Carothers and the Development of Nylon: Two great pages telling the story of how Wallace Carothers and his DuPont colleagues developed nylon.

[PDF] Synthetic Fiber Manufacturing by Charles B. Weinberger, Dept of Chemical Engineering, Drexel University. August 30, 1996. A good overview of fiber-production techniques for an undergraduate audience. It covers synthetic fibers such as nylon and polyester, as well as things like fiber-optic cables. [Archived via the Wayback Machine.]

Articles

February 23, 1935: Sheer bliss by Tony Long. Wired, February 28, 2011. Celebrating the first production of nylon by Du Pont.

Julian W. Hill, Nylon's Discoverer, Dies at 91 by David Stout. The New York Times, February 1, 1996. An obituary of Wallace Carothers' important colleague.

New Nylon Fiber Found: Strong, Warm Fabrics Believed Possible From Product: The New York Times, November 23, 1946. This article from the Times archive hails the discovery of a revolutionary new type of nylon.

Books

Patents

If you're really interested, and your knowledge of chemistry is reasonably advanced, you'll find Wallace Carothers' patents for polyamides worth a look:

Please do NOT copy our articles onto blogs and other websites

Text copyright © Chris Woodford 2010, 2015. All rights reserved. Full copyright notice and terms of use.

"Nomex," "Kevlar," "Zytel," and "DuPont" are trademarks or registered trademarks of E. I. du Pont de Nemours and Company.

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Nylon - The science of synthetic textiles

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by Chris Woodford. Last updated: January 31, 2019. If wood is the world's most versatile natural material, nylon is probably the most useful synthetic one. It's a plastic that can be molded into everyday products or drawn into fibers for making fabrics-and its launch in the late 1930s truly changed the world.

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Diaper Wars: Cloth vs. Disposable - Healthline

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Diaper Wars: Cloth vs. Disposable - Healthline

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Whether you choose cloth or disposable, diapers are part of the parenting experience.

Newborn babies can go through 10 or more diapers every day, and the average child won't begin potty training until about 21 months old. In fact, the U.S. Environmental Protection Agency (EPA) estimates that the average baby will use 8,000 diapers before potty training.

Fortunately, there's no right or wrong decision when it comes to diapers. You can choose one or the other or a combination of both if that suits your baby, lifestyle, and budget.

Here's what to know about cloth and disposable diapers to make the right choice for you and your baby.

Cloth Diapers

Today's reusable cloth diapers come in a number of styles.

Most options feature a waterproof cover or outer layer and an absorbent insert or inner layer. Some inserts are snapped into the cover, while others fit into a pocket. There are also all-in-one diapers that combine the cover and insert in one system.

There are a few different materials for the inner and outer layers of a cloth diaper.

Natural Fibers

This material is derived from plants or animal materials. While they may be more expensive, they wash well.

Synthetic Materials

This is a man-made option. They can be less expensive than natural fibers, but may hold on to odors.

The material from which it's constructed impacts a cloth diaper's absorbency.

The Covers

Cover options are typically constructed of the following.

Polyurethane laminate (PUL)/thermoplastic polyurethane (TPU): These covers are made from lamented polyester. They're widely used and affordable. They're waterproof, but not particularly breathable.

Microfiber: These diaper covers are made of soft polyester.

Cotton: These PUL/TPU options are covered with cotton for softness and come in a variety of prints. This option is more prone to leaks.

Fleece: Another polyester option, fleece covers allow for more air circulation.

Wool: A naturally antimicrobial choice, wool covers are breathable and quite absorbent.

Nylon: This option typically offers a good mix of breathability and absorbency.

Diaper inserts come in a range of materials as well, including:

Some inserts are disposable, which can be a good option for parents who want to use cloth diapers as inexpensively as possible. Absorbencies will vary depending on the material.

To care for cloth diapers, follow the individual manufacturer's instructions. In general, solid waste is dumped in the toilet and the insert and cover are rinsed in cold water, then soaked in a mild detergent and bleach solution before being washed. Be sure to wash cloth diapers separately from the rest of your laundry.

Disposable Diapers

Disposable diapers are available from many manufacturers, but the design doesn't vary. It's a single construction made of a soft liner that wicks wetness, an absorbent core, and a waterproofing outer layer. Today's disposables are very thin and light. After use, they simply go in the trash.

There's an environmental toll - all disposables go to the landfill. The production of disposable diapers can be environmentally costly as well. Nearly 70 percent of a disposable diaper is made of paper, and that comes from trees. The other 30 percent is often derived from petroleum, which is a nonrenewable resource.

Eco-friendly brands of disposable diapers are free of ingredients like perfumes, latex, and chlorines. Some of them have a percentage of compostable materials as well. These diapers are more expensive than traditional diapers, but tend to be more responsibly manufactured.

The Pros and Cons

Price

Cloth diapers are a one-time purchase.

According to Consumer Reports, you'll save hundreds of dollars over disposable diapers. Disposables can cost between $1,500 and $2,000 or more in the few years your child wears them, and it's even higher for eco-friendly brands.

If you choose to use a cloth diaper service that washes and returns the soiled diapers, you'll also save on the cost of water, power, and detergents for your laundry machine. But diaper services can be costly because you pay more for the convenience factor.

Eco Factor

With cloth diapers, you aren't adding to the landfill. That's where disposable diapers end up, and they don't all biodegrade quickly.

According to the EPA, disposable diapers will be in landfills for centuries. Cloth diapers, meanwhile, require a lot of electricity and water to keep them clean.

Convenience

Modern cloth diapers are quick and easy to use, just like disposables. However, they aren't as readily available for purchase, and you'll need to say organized to keep clean diapers on hand. If you're out and your baby soils a diaper, you can't just throw it away like a disposable.

Comfort and Health

There have been reports of children reacting to ingredients in traditional disposable diapers.

However, there are many brands that are free of chlorine, latex, perfumes, and dyes. With cloth diapers, you can be certain of what materials you're using. But because cloth diapers are less absorbent than disposables, children can be more prone to diaper rash. No matter which diaper you use, don't leave your baby in a soiled or wet diaper for too long.

The Takeaway

Choosing the right diaper is a personal decision. It's important to consider the pros and cons of each to decide what will work best for you.

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Cloth Diapers vs. Disposable: Which Is Better?

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Whether you choose cloth or disposable, diapers are part of the parenting experience. Newborn babies can go through 10 or more diapers every day, and the average child won't begin potty training until about 21 months old. In fact, the U.S. Environmental Protection Agency (EPA) estimates that the average baby will use 8,000 diapers before potty training.

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Cloth vs. Disposable Diapers - Appropedia

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Cloth vs. Disposable Diapers - Appropedia

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This page summarizes life cycle assessment (LCA) studies that focus on how cloth and disposable diapers differ in cradle-to-grave impacts. Life cycle analysis follows resource consumption and environmental impacts from a product's "cradle to grave", meaning, from the product's creation to disposal (Figure 1).

Every diaper type has differing associated impacts for production, use, and disposal. Impacts are broken into four categories: water consumption, energy consumption, raw materials consumption, and solid waste. Raw materials consumption describes natural and man-made resources needed for production of the diaper type and solid waste describes specific impacts related to disposal of diaper type. These impacts are all related to production, use, and disposal of each diaper type.

One primary goal for this page is to communicate how complicated the relationships are between resources, environmental health, and product consumption. It is impossible to quantify all cradle-to-grave effects for a product. Hopefully, the reader (YOU!) will read this summary and not only understand how to make more informed decisions, but understand how a mundane item like a baby diaper can be involved in complex environmental impacts relationships related to diaper production, diaper use, AND diaper disposal practices.

Disposables: Throw-away and Compostable Diapers

Disposable diapers are composed of various wood and plastic products. The composition of a disposable diaper can be approximated as 43% wood pulp (Fluff pulp), 27% super absorbent polymer (SAP), 10% polypropylene (PP), 13% polyethylene (PE), and 7% tapes, elastics and adhesives (Figure 2; )

Life Cycle Overview

The LCA for disposable diapers must first account for resource impacts from production of diaper materials, which can become exhaustive. Figure 3 is a schematic diagram representing a disposable diaper LCA which begins with the five basic diaper components. All resource categories are needed for the production of the diaper components and for the assimilation of the diapers from the components. Resources must also be accounted for after diaper production: packaging, shipping, sales, use, and disposal. Depending on regional waste management resources, several types of disposal methods may be available.

Water Consumption

Disposable and compostable diapers consume less water than reusable cloth diapers. Production processes are designed to minimize water consumption in manufacturing. A break down of the water consumption in the life cycle analysis for one child is shown in Table 1, the data assumes there are 4.6 changes a day until the child is 2.5 years of age.

Table 1: Water uses associated with disposable diapers

While the production of disposable diapers requires more energy than production of reusable types, disposable diapers do not need to be laundered. Laundering the reusable diapers requires additional energy for washing and drying that disposables do not, unless they are line dried.

Energy Consumption

Energy consumption for disposable diapers is tied into the coal and crude oil used to create the energy needed to harvest the raw materials, manufacture, transport, and disposal of the diapers. Table 2 shows the amounts of crude oil and coal used in one life cycle stage.

Table 2: The coal and crude oil use for the life cycle of disposable diapers used for one child until the age of 2.5 years assuming 4.6 diaper changes were made per day.

Raw Materials Consumption

Modern forest management processes include measures of sustainability such as replanting. Also, diaper wood pulp may come from forest waste products such as forest thinnings and sawmill waste.

Here is a breakdown of forest product usage :

Of total timber harvest 47% is forest products (non fuel products).

Of forest products, 30% is pulpwood product.

Of pulpwood product, 9% is hygiene product.

Of hygiene product, 2% is diaper product.

The above breakdown can be used to estimate that diapers use 0.05% of total wood product (fuel and non-fuel).

Solid Waste

Solid waste has been the primary historical focus for disposable diaper environmental impact. Not only is the diaper product being thrown away, but untreated feces and urine as well.

Disposable diapers produce more solid waste than reusable diapers. Even if excreta are flushed before disposal of the diaper, the diaper itself still goes to the landfill. While most disposable diapers can decompose readily within five months, as they are just wood products and cotton, the absorbent gels and plastic components do not. Compostable disposable diapers however, generally decompose completely within five months of disposal.

Compostables, Another Viable Alternative?

Compostable diapers have just emerged into the commercial market, and offer another potential alternative to both disposable and reusable diapers. Compostable diapers are still easily disposed of, similar to conventional disposable diapers, and do not need laundering; this makes them very attractive to consumers. However, compostable diapers are not without their shortfalls. While compostable diapers do not generally last more than five months in a landfill, they require even more raw product consumption than conventional disposables.

Cloth Diapers: Home Washed and Diaper Service Diapers

Cloth diapers differ from disposables in that they are intended to be reused, thus cloth diapers are viewed as the more environmentally conscious alternative than disposables. Cloth diapers are usually made with cotton or terry cloth. The water use and energy consumption associated with cloth diapers are in different phases in the life cycle than that of a disposable diaper. Cloth diapers are washed either at home or sent out to be washed commercially. Where available, information on the life cycle differences between these two use patterns of reusable diapers will be addressed.

Life Cycle Overview

The life cycle analysis of a reusable diaper starts with the raw materials and extends into the manufacture, transport, purchase, use, and final disposal.

Water Consumption

Due to the need to launder between uses, water consumption is much higher over the life of reusable diapers. A break down of the water uses associated with cloth diapers is in Table 3.

Table 3: Water uses associated with cloth diapers washed at home and commercially for one child until the age of 2.5 years

Energy Consumption

Energy consumption is in general considerably less for reusable diapers when compared with disposable and compostable diapers. The primary source of energy usage associated with reusable diapers is from laundering, where disposables are primarily from manufacturing processes. Table 4 shows the break down of energy use for reusable diapers.

Table 4: Energy differences between home and commercially washed diapers

It should be noted: if individuals launder their own disposables and line dry, rather than using a gas or electric drier, energy consumption would be reduced.

Raw Materials Consumption

Raw materials consumption for reusable diapers is generally lower than that of disposables. The primary component of reusable diapers is cotton; cotton use for cloth diapers is slightly higher for commercially laundered diapers than those laundered at home (diapers are replaced more often when laundered commercially).

Solid Waste

While the amounts of excreta are not different between reusable and disposable diapers, cloth diapers produce considerably less solid waste (from lack of being discarded in a landfill) than disposable types. Reusable diapers are often used for a period of two and a half before disposal; generally the amount of time a child spends in diapers. Commercially laundered cloth diapers have a shorter span of use, and therefore produce more waste than home washed.

Conclusions

To emphasize how complicated an LCA can be, and how the "golden" solution does not emerge for a more favorable choice between cloth and reusable diapers Table 4 shows the different impact topic comparisons.

Table 4: Life-Cycle Analysis of Disposable and Reusable Diapers (based on weekly diaper needs)

Infinite statements representing the above table can be made to represent the relationships between diaper type and resource impact. Here are two broad statements:

Disposable diapers create less atmospheric emissions, waste water effluents, and solid waste (feces processing) than reusable diapers.

Reusable diapers use less raw material for production and create less post consumer waste than disposables.

These statements do not necessarily present a clear solution to the question, "Which diaper type is better for the environment?". Assessing which resource is more valuable, or more sensitive to impact is difficult but suggested for further analysis.

References Cited

1. The Proctor and Gamble Company, "Disposable and Reusable Diapers--A Life-Cycle Analysis", World Resources Institute, 1994

2. Olive, Rachel; "A Life Cycle Analysis of Disposable, Reusable and Compostable Nappies Under Brisbane Conditions", Dept. of Chemical Engineering, University of Queensland, 2004.

3. European Disposables and Nonwovens Association, "Diapers--Health Benefits and Environmental Aspects", 2000.

4. Aumonier, Simon and Collins, M.; "Life Cycle Assessment of Disposable and Reusable Nappies in the UK", Environmental Agency, May 2005.

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This page summarizes life cycle assessment (LCA) studies that focus on how cloth and disposable diapers differ in cradle-to-grave impacts. Life cycle analysis follows resource consumption and environmental impacts from a product's "cradle to grave", meaning, from the product's creation to disposal (Figure 1). Every diaper type has differing associated impacts for production, use, and disposal.

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How Disposable Nappies/Diapers Are Made - National Geographic

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How Disposable Nappies/Diapers Are Made - National Geographic

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Don't Pooh-Pooh My Diaper Choice - Stanford Alumni

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Don't Pooh-Pooh My Diaper Choice - Stanford Alumni

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Asked by Katie Cooke, Littleton, Colo.
I was raised in disposable diapers, as was my sister and all of our little cousins. Until I started researching this question, I thought that I would someday dress my little tykes in disposable diapers as well. I assumed that cloth diapers would be much better for the environment, but returning to the middle ages of childcare just seemed unacceptably messy. Still, I started objectively, looking at how the two options are made.

What goes into a diaper? Electricity, water and raw material. And how different are the two diaper options? Disposable diapers generate vastly more landfill waste than reusables, of course. But it takes a lot more water to make a cloth diaper than a disposable one, mostly to grow and process the cotton. When the water used to wash the reusables is added to the equation, cloth diapers require twice as much water as disposable diapers do. I was shocked when I found this gem of information hidden in the calculations of a U.K. Environment Agency report comparing cloth and disposable diapers.

The same report calculated every resource used, from water and energy to plastics and cotton, throughout production, use and disposal of the respective diaper products. This more comprehensive analysis calculated the relative environmental impact on everything from global warming to toxic waste. I'll get into the details in the Nitty-gritty, but here's the real surprise: cloth and disposable nappies come to a near tie in overall environmental impact.

Cloth and disposables have similar global warming impact, though for different reasons. The manufacturing of disposable diapers has a larger carbon footprint, but the electricity used to wash reusable diapers cancels out most of the difference. Disposables have greater impact on ozone depletion, thanks to CFCs released as they decompose in the landfill. But cloth diapers generate more toxic waste that can impact human health, because of the electricity, detergent and softener used to wash them.

So what will I wrap my kids little buns in? I don't want to contribute to the thousands of tons of diapers sent to landfills every year. But the necessary washing of cloth diapers may be equally problematic, especially in drought-stricken areas. Cloth diapers will always use more water than disposables, but they also offer more opportunities to decrease overall environmental impact-by using more efficient washers, and cleaner soaps and power sources.

A new design of cloth nappies with a compostable liner may be the solution to diaper sustainability. You can wash the outer cloth diaper less frequently, and either compost the soiled inner layer or flush it down the toilet. gDiapers, a specific brand, has "Cradle-to-Cradle" certification, validating its biodegradable diaper technology. For even less impact, buy the compostable liners and fashion your own cloth nappies from old T-shirts or sweaters. With a DIY diaper, you can dress up your baby's bum in a funky old concert t-shirt. They can even represent your alma mater.

And don't forget: Diapers are just one product your infant will need. Reducing your child's other impacts can be as simple as looking to Craigslist, consignment stores and baby swaps before you purchase new clothes and toys. When in doubt, reduce, reuse and recycle-and teach your kids to do the same.

Interested in a little more about the unexpected impact of green-sounding options? Check out this Ted Talk by Catherine Mohr on the related paper towel vs. cloth rag dilemma.

Grace Goldberg, '13, is a coterminal student in earth systems.

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Don't Pooh-Pooh My Diaper Choice: Essential Answer

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Asked by Katie Cooke, Littleton, Colo. I was raised in disposable diapers, as was my sister and all of our little cousins. Until I started researching this question, I thought that I would someday dress my little tykes in disposable diapers as well.

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Which is Greener? It's Not What You'd Expect - Oregon Public Broadcasting 

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Which is Greener? It's Not What You'd Expect - Oregon Public Broadcasting 

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University of Oregon chemistry professor David Tyler blew conventional environmental wisdom out of the water in Hillsboro last night.

He gave a talk that focused on life cycle assessments that tally the total environmental impacts of everyday choices: Which bag you use for your groceries, which milk container you buy, which cup you use for your coffee, which car you drive...

The assessments account for the impacts of a product throughout it's entire life: from the first steps of obtaining the raw materials to the waste products leftover after it's been used. They evaluate the total energy use, contributions to global warming, ocean acidification, air and water pollution, for example. They're usually pretty expensive and time consuming.

And the conclusions aren't what you'd expect. They show plastic bags are greener than paper bags, disposable plastic cups have fewer impacts than reusable ceramic mugs, and owning a dog is worse than driving an SUV.

Surprise! Apparently, we're not as green as we thought.

"Most people I know want to do the right thing with regard to the environment," Tyler said at the outset of his talk. "What is the right thing?"

One of the biggest surprises from the life cycle assessments he's studied is that plastic often has fewer environmental impacts than paper, glass or cotton.

"There is no basis for believing that plastics are considerably more harmful to the environment than traditional materials such as paper, glass or cloth," Tyler said. "In many cases, products made from plastic are more sustainable."

Tyler isn't under any illusions that plastic is good for the environment. He listed the problems it causes because it doesn't readily biodegrade, it contains harmful chemicals such as Bisphenol A and phthalates that leach out and disrupt hormones in people and wildlife, and it takes non-renewable petroleum to make it.

However, he said, only 3 percent of the petroleum used in the U.S. is going toward making plastic while 87 percent goes toward energy and transportation.

"If we stop using plastics tomorrow, it would only have a small impact on our use of petroleum," he said.

A life cycle assessment in Australia found single-use plastic bags have fewer impacts than paper grocery bags. They use less energy and resources and produce fewer pollutants.

The most sustainable grocery bag option, according to that assessment, is a reusable bag made of recycled plastic. The next best is cotton, then regular plastic bags and then paper.

"They found paper bags are the worst thing we can do for the environment," he said. Yet in cities that have banned plastic bags, grocery stores are now offering paper bags instead.

The same counter-intuitive conclusion came out of another life cycle assessment that found ceramic mugs take so much energy to produce that we're better off using disposable plastic cups. Paper cups actually require more process water and chemicals to make than styrofoam, the study found.

And your milk container? A life cycle assessment found biodegradable plastic produces almost twice as many greenhouse gases than regular plastic, which has fewer climate impacts than cardboard and glass.

The best option, he said, is actually the rectangular "tetrapack" that's commonly used to package soy and rice milk.

But life cycle assessments don't account for everything, said Tyler.

"In every category, the plastic bag looks pretty good," he said. "But what about quality of life? People just don't like the fact that the plastic does not degrade. It impacts our life in the form of litter."

The life cycle analyses of grocery bags don't account for what kind of food goes in the grocery bag either, Tyler noted. And that has a much bigger impact than any of your grocery bag choices.

"What goes into the bag is going to make the biggest impact," he said. "If you eat a vegetarian diet, you have a much smaller impact."

Life cycle assessments have produced some really interesting details about the impacts of everyday life, Tyler reported:

They've found that the impacts of food miles - the distance food has to travel to get to you - are negligible.

They've found one pint of beer, roughly 1 pound of liquid, produces the equivalent of 3.8 pounds of carbon dioxide.

One assessment determined that a six-pack of Fat Tire beer produces the equivalent of 11 pounds of carbon dioxide - the weight of a small bowling ball.

Another found that one pair of Levi's 501 jeans produces the equivalent of 72 pounds of carbon dioxide and 3,500 liters of water.

They haven't been kind to cotton. Growing cotton has major impacts in the form of pesticides. Roughly 25 percent of all the pesticides used in North America are used on cotton crops.

And they've found that having a dog is a bigger environmental impact than driving an SUV.

"Anything involving agriculture is hard on the environment," Tyler said. "Food for the dog makes it a larger impact than a Toyota Land Cruiser."

Tyler quoted one of his students asking him: "So you're saying I should go home, shoot my dog, wear no pants and drive a sport utility vehicle?"

No, he said. The thing about life cycle assessments is they don't consider cost, technical performance or the political and social acceptance of the items in question.

In the end, he said, society makes its own calculations.

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Which Is Greener? It's Not What You'd Expect

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University of Oregon chemistry professor David Tyler blew conventional environmental wisdom out of the water in Hillsboro last night. He gave a talk that focused on life cycle assessments that tally the total environmental impacts of everyday choices: Which bag you use for your groceries, which milk container you buy, which cup you use for your coffee, which car you drive...

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Why Glass Jars Aren't Necessarily Better for the Environment Than Plastic Ones - The Washington Post

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Why Glass Jars Aren't Necessarily Better for the Environment Than Plastic Ones - The Washington Post

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Plastic vs. Glass - Packaging of the World

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Plastic vs. Glass - Packaging of the World

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Packaging of the World - Creative Package Design Gallery

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Written by Katherine Golovinova, Marketing manager of Allinpackaging creative packaging.

From an environmental point of view, most people have already got their answer in mind when it comes to using plastic or paper, the answer of which is neither, but what about plastic or glass? While some people still think that glass is better than plastic because of its eco-friendliness, plastic has its fair share of fans too, mainly because of one reason. Plastic and glass are both recyclable, but since glass can only be recycled and turned into more glass, it limits its options. On the other hand, since plastic loses its integrity, it can be recycled into a number of products from carpet filling to plastic lumber and so on.

Disadvantages of Glass Packaging
While glass is used in supermarkets and stores to package food stuff such as, oils, spices and so on, when it comes to packaging perishables for the long-haul, it does have its drawbacks. The following are some of the disadvantages of using glass for packaging.

Weight
First of all, glass is heavier than plastic. This means that more trips are required when transporting packaged goods. This, also in turn, means a greater environmental impact. Not only is glass heavier, it is also heavy for the end consumer who needs to carry what they have purchased from point A (the superstore) to point B (their home).

Fragile
Fragile takes on a whole new meaning when using glass containers for storing food items. As we have all learnt from an early age, glass has a tendency of smashing easily, which means that if a glass bottle or canister is knocked accidently on the floor it will break easily, leaving a mess behind. Apart from that, glass is also more slippery to the touch as compared to plastic. This means that it is more likely to be dropped than a plastic container or other packaging material.

Unsafe
Glass is also more dangerous when broken as compared to other packaging material. Broken glass can cut a person's skin and can at times, also be life threatening. This is a danger that is very true for those working in factories, shops and even transportation and packaging operative who are responsible in handling them.

Types of Plastic Containers
Plastic containers come in several types. Some of the styles that they can be found in are Boston rounds, cylinders, jugs, modern rounds, oblongs, packers, squares, straight sided rounds, vials, wide mouth rounds. This kind of variety makes it a better choice for those with different storing needs. The following are some examples of plastic containers used in everyday life.

Plastic Canisters
Unlike cardboard boxes, plastic canisters don't get damaged with water or heat. In addition, plastic canisters are also air tight, so long as the lid is kept closed. This helps in keeping whatever is inside fresh and allows people to store items in bulk without the fear of the contents getting stale. Additionally, clear plastic canisters are often preferred because it is easier to identify what is stored inside them without the need to open the lid.

Plastic Bottles
Plastic bottles are containers that are made from a polymer resin which is similar to polyester and is used to store water or other liquids. The main reason why plastic bottles are preferred is because they are light weight, which makes them easier to carry around. Plastic bottles are also exceedingly durable, which means they can be dropped without breaking.

And finally, plastics in general provide brilliant thermal insulation. This means that the liquids inside a plastic bottle can keep their temperature better than in containers made of other materials. This makes plastic bottles an excellent choice for storing cold or hot liquids.

Plastic Trays
Whether using a tray for the school canteen or in the baking and food service industry, living up to certain hygiene standards is a must. One of the best ways of maintaining good hygiene is by using plastic trays to store, transport or distribute cooked goods. Plastic trays are gaining in popularity because they can be used, washed and reused multiple times. Because it provides the users with a form of cheap maintenance, businesses in the food industry can avoid spending extra money on buying new trays to replace their old ones.

Plastic Food Containers
Almost everyone has had the unfortunate experience of having to smell an unpleasant odor after opening their fridge. The unpleasant odor is caused by food that has gone bad, one of the many advantages of storing your food items in good quality plastic containers is that it is able to keep the stench of bad food inside the container.

Keeping food properly sealed so that it is able to remain fresh for longer is just one of the benefits of using plastic food containers. While using a plastic food container, one can either store perishables by freezing them or cook food and then store it. The food can always be thawed later on and reheated in the microwave oven.

The following are some of the benefits of using plastics for storing and packaging food.

Extra Storage
Plastic containers allow you to buy food in bulk, which allows you to save money and get access to discounts and other price reductions that come along with buying in bulk.

Absorption of Flavors
When plastic is used to store perishable items, it is able to absorb the smells and tastes of them, which means that foods with strong flavors, such as curry or tomato soup can be stored without its odor spreading throughout the whole fridge.

Advertising Your Brand
Plastic packaging materials are the most common materials that are used for branding strategies mainly because they are easier to print on. Since the printing on plastics can be done easily, it diminishes the cost and offers a packing solution that enables you to promote your brand as well.

Plastics are Recyclable
Over forty percent of the plastic made is recycled, as compared to only twenty percent of glass containers. Recycling of glass has peaked since the mid nineties, and the percentage of glass being recycled each year has declined, while the recycling of plastic is growing.

About the author
Katherine Golovinova is the Marketing manager ofAllinpackaging creative packaging.
You can connect with her onGoogle+.

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Plastic vs. Glass - Why Plastic Containers Are Better

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Written by Katherine Golovinova, Marketing manager of Allinpackaging creative packaging. From an environmental point of view, most people have already got their answer in mind when it comes to using plastic or paper, the answer of which is neither, but what about plastic or glass?

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Environmental Impact of Glass Production - Environmental Impact

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Environmental Impact of Glass Production - Environmental Impact

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Other environmental issues are water pollution, the use of non-renewable natural raw materials such as sand and minerals, production of solid waste and emission of volatile organic compounds (used in production of mirrors and coatings).

Although a lot has already been achieved, further reductions in emissions of SO₂, dust particles, NOx and CO₂ are still the main environmental objectives for our flat glass activities. Minimising and controlling these emissions in an integrated way is a complex matter. The development of environmental techniques is still ongoing, and AGC Glass Europe actively participates in the dynamic process of developing new techniques.

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Other environmental issues are water pollution, the use of non-renewable natural raw materials such as sand and minerals, production of solid waste and emission of volatile organic compounds (used in production of mirrors and coatings). Although a lot has already been achieved, further reductions in emissions of SO2, dust particles, NOx and CO2 are still the main environmental objectives for our flat glass activities.

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by Chris Woodford. Last updated: January 19, 2021.

Now you see it, now you don't. Glass is a bit of a riddle. It's hard enough to protect us, but it shatters with incredible ease. It's made from opaque sand, yet it's completely transparent. And, perhaps most surprisingly of all, it behaves like a solid material... but it's also a sort of weird liquid in disguise! You can find glass wherever you look: most rooms in your home will have a glass window and, if not that, perhaps a glass mirror... or a glass lightbulb. Glass is one of the world's oldest and most versatile human-created materials. Let's find out some more about it.

Photo: Glass riddle: How does something transparent to light appear colored? The colors in this glass aren't really there! Glass lenses refract (bend) light rays of different wavelengths by different amounts, causing spectral colors to appear. This is a closeup of a Fresnel lens from a lighthouse.

What is glass?

Photo: Stained glass is made by adding salts of metals such as iron, manganese, chromium, and tin to the ingredients of molten glass to give it a variety of attractive colors. This stained glass window, designed by artist Edward Burne-Jones, is in St Philip's Cathedral, Birmingham, England.

Believe it or not, glass is made from liquid sand. You can make glass by heating ordinary sand (which is mostly made of silicon dioxide) until it melts and turns into a liquid. You won't find that happening on your local beach: sand melts at the incredibly high temperature of 1700°C (3090°F).

When molten sand cools, it doesn't turn back into the gritty yellow stuff you started out with: it undergoes a complete transformation and gains an entirely different inner structure. But it doesn't matter how much you cool the sand, it never quite sets into a solid. Instead, it becomes a kind of frozen liquid or what materials scientists refer to as an amorphous solid. It's like a cross between a solid and a liquid with some of the crystalline order of a solid and some of the molecular randomness of a liquid.

Glass is such a popular material in our homes because it has all kinds of really useful properties. Apart from being transparent, it's inexpensive to make, easy to shape when it's molten, reasonably resistant to heat when it's set, chemically inert (so a glass jar doesn't react with the things you put inside it), and it can be recycled any number of times.

How is glass made?

Artwork: Glassmaking simplified: mix and heat sand and recycled glass with calcium carbonate and sodium carbonate.

When US scientists tested a prototype of the atomic bomb in the New Mexico desert in 1945, the explosion turned the sand in the immediate area of the impact into glass. Fortunately, there are easier and less extreme ways of making glass-but all of them need immense amounts of heat.

In a commercial glass plant, sand is mixed with waste glass (from recycling collections), soda ash (sodium carbonate), and limestone (calcium carbonate) and heated in a furnace. The soda reduces the sand's melting point, which helps to save energy during manufacture, but it has an unfortunate drawback: it produces a kind of glass that would dissolve in water! The limestone is added to stop that happening. The end-product is called soda-lime-silica glass. It's the ordinary glass we can see all around us.

Photo: Borosilicate glass, such as this PYREX® jug (back), can withstand extreme changes of temperature, unlike normal glass (front), which shatters. The ordinary glass jar at the front is quite a bit thinner and considerably lighter. You can also see, very clearly that the borosilicate glass is a slightly blueish color (as is the boron oxide from which it's made).

Once the sand is melted, it is either poured into molds to make bottles, glasses, and other containers, or "floated" (poured on top of a big vat of molten tin metal) to make perfectly flat sheets of glass for windows. Unusual glass containers are still sometimes made by "blowing" them. A "gob" (lump) of molten glass is wrapped around an open pipe, which is slowly rotated. Air is blown through the pipe's open end, causing the glass to blow up like a balloon. With skillful blowing and turning, all kinds of amazing shapes can be made.

Glass makers use a slightly different process depending on the type of glass they want to make. Usually, other chemicals are added to change the appearance or properties of the finished glass. For example, iron and chromium-based chemicals are added to the molten sand to make green-tinted glass. Oven-proof borosilicate glass (widely sold under the trademark PYREX®) is made by adding boron oxide to the molten mixture. Adding lead oxide makes a fine crystal glass that can be cut more easily; highly prized cut lead crystal sparkles with color as it refracts (bends) the light passing through it. Some special types of glass are made by a different manufacturing process. Bulletproof glass is made from a sandwich or laminate of multiple layers of glass and plastic bonded together. Toughened glass used in car windshields is made by cooling molten glass very quickly to make it much harder. Stained (colored) glass is made by adding metallic compounds to glass while it is molten; different metals give the separate segments of glass their different colors.

Is glass a solid... or a liquid?

Artwork: Top: In a regular crystalline solid, the atoms are arranged in a neat and predictable way. Bottom: In an amorphous solid, such as glass, the arrangement is much more random.

It's a very interesting question.

The answer is both-and neither! There are widely differing opinions on how to refer to materials such as glass that seem to be a bit like liquids in some ways and a bit like solids in others.

In schools and in books, we tend to learn that solids all have a fixed structure of atoms.

In fact, there are different kinds of solids that have very different structures and not everything we describe as "solid" behaves in exactly the same way. Think of a lump of iron and a lump of rubber. Quite clearly they are both solids, and yet the rubber is very different from the iron. Inside, rubber and iron have their atoms (in the case of iron) and molecules (in the case of rubber) arranged in totally different ways. Iron has a regular or crystalline structure (like a climbing frame with atoms at the corners), while rubber is a polymer (made from long chains of molecules loosely connected together). Or think of water. As you may have discovered, water is an almost unique solid because it expands to begin with when it freezes. In short, not everything fits neatly into our ideas of solid, liquid, and gas and not all solids, liquids, and gases behave in a nice, neat, easy-to-explain way. The exceptions are the things that make science really interesting!

Amorphous solids

Let's return to glass. Peer through a microscope inside some glass and you'll find the molecules from which it's made are arranged in an irregular pattern. That's why glass is sometimes referred to as an amorphous solid (a solid without the regular crystalline structure that something like a metal would have). You may also see glass described as a "frozen supercooled liquid". This is another way of saying "glass is a liquid that has never set", which is the puzzling statement you'll sometimes find in science books. We could say glass is a bit like a liquid and a bit like a solid. It has an internal structure that is somewhere between the structure of a liquid and a solid, with some of the order of a solid and some of the randomness of a liquid.

Glass is by no means the only amorphous solid. It's possible to make a type of water called amorphous ice that could be described as in-between solid (water) and liquid (ice). You do this by cooling water very quickly. The ice forms so fast that it doesn't have time to build up its normal, crystalline structure. So what you get looks like ice but behaves in some ways like liquid water. Other substances can be made into amorphous solids too. Solar cells are often made from something called amorphous silicon.

Photo: A solar panel made from amorphous silicon. Photo by Dennis Schroeder courtesy of NREL (US Department of Energy/National Renewable Energy Laboratory) (photo id #22143).

What do we use glass for?

Photo: Glass can be used to recycle other materials. Uranium glass has an unusual yellow-green color and glows in ultraviolet light. These glass pieces were made using waste uranium from the cleanup of the Fernald uranium processing plant near Cincinnati, Ohio, USA. Vitrification (turning a material into glass) is one way to dispose of nuclear waste safely. Picture by courtesy of US Department of Energy.

Glass starts your day with a sparkle: a glance at your watch, a gaze through the glaze at the sun or the rain, a frown in the mirror, a song from the shower, as you wash with water trickling down warm from the solar panels on the roof. Glasses pack the breakfast table, which might, itself, be made from smoked glass, and there are bottles and jars of all shapes and colors. Making breakfast in your kitchen, you might be using a glass-ceramic cooktop or a microwave with a metal-lined window to keep the waves inside. Maybe you're watching croissants warm through the Pyrex oven door? (And is that a glass teapot?)

When you check your email over breakfast (bad habit), speed-of-light Internet data zips to your home through optical fibers, just as sunlight streams through the heat-reflective windows that keep you cool. You read the words through the glass LCD panel of your laptop or the toughened gorilla glass of your smartphone, both charged by solar energy from photovoltaic panels on the roof. Talking heads are muttering at you through the TV screen in the corner.

Then you set off for work or school, in a glass-wrapped car, bus, train (perhaps even helicopter), hunched under low-energy lamps covered by glass to make them last. If you're driving, the highway you're roaring down could be made from aggregates and asphalt including recycled glass; even the white stripes down the middle use tiny glass beads to make them shine in your headlights. Maybe you drop in the bank or the post office on your way, smiling at the cashier behind her bulletproof window, as you make a quick copy of your driving licence (which you carelessly leave behind on the glass plate of the photocopier).

Photo: Glass brings the outside in! This is the wonderful Wayfarers Chapel in Rancho Palos Verdes, California, designed by Lloyd Wright (son of Frank Lloyd Wright). Picture from The Jon B. Lovelace Collection of California Photographs in Carol M. Highsmith's America Project, Library of Congress, Prints and Photographs Division.

If it's a modern building, your office or school might be a mini glass cathedral; we think of glass as brittle and fragile, but toughen it the right way and you can make walls, floors, roofs, and staircases from it; shops show their wares through huge, laminated panels, polished to perfection.

And that's only a tiny selection of the things glass does for us. There are loads more places you'll find it hiding, from the bulbs in thermometers and the cermet fillings in teeth to the fiberglass hulls of boats, the "sandpaper" we use for decorating (which is often glasspaper), and even the strain gauges that warn us when buildings are cracking. Clear, clean, attractive, unreactive, cheap, strong, and effective. What more could you want? Glass is one of those magic materials we absolutely take for granted; everywhere and nowhere-"invisibly transparent," so we don't even notice that it's there!

If you liked this article...

... you might like my books. My latest one is Breathess: Why Air Pollution Matters and How it Affects You.

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Books

The Glass Bathyscaphe: How Glass Changed the World by Alan MacFarlane and Gerry Martin by Alan Macfarlane and Gerry Martin. Profile, 2002. Explores the history of glass from ancient to modern times. I believe this is the same book (differently packaged) asGlass: A World History by Alan Macfarlane and Gerry Martin. University of Chicago Press, 2002.

Introduction to Glass Science and Technology by J.E. Shelby. Royal Society of Chemistry, 2005. An undergraduate text covering the chemical and materials-science aspects of glass. Covers the various different types of glass and their mechanical, optical, and other properties.

Glass: Mechanics and Technology by Eric Le Bourhis. Wiley-VCH, 2014. Covers the history, structure, properties, and applications of glass.

Glass Science by Robert Doremus. Wiley, 1994. A classic single-volume guide to the science of amorphous, glassy solids.

Atoms Under the Floorboards by Chris Woodford. Bloomsbury, 2015. If you're looking for a more light-hearted approach, my recent book explores the wonders of glass in "Chapter 8: Amazing Glazing." You might be able to read some it online on Google Books by following this link.

Articles

For the Sake of Art: Risk and Reward at 2,000 Degrees by Gloria Dawson. The New York Times, September 1, 2016. This slideshow goes behind the scenes at UrbanGlass, an experimental glass workshop in New York City.

Glass works: how Corning created the ultrathin, ultrastrong material of the future by Bryan Gardiner, Wired, September 24, 2012. The origins of a remarkable glass-ceramic material that eventually became smartphone Gorilla Glass.

Blow by Blow: GlassLab Comes to Governors Island by Julia Felsenthal. The New York Times, July 3, 2012. Introducing GlassLab at the Corning Museum of Glass.

Willow Glass: ultra-thin glass can 'wrap' around devices by Katia Moskvitch, BBC News, June 5, 2012. Corning reveals a thin and flexible glass for next-generation displays.

The Glass Whisperer by Andrea Truppin. The New York Times, January 27, 2005. The world of Michael Davis, a specialist in restoring antique glass.

Podcasts

Patents

For deeper technical detail, try these:

US Patent 1,304,623: Glass by Eugene C. Sullivan and William C. Taylor, Corning, May 27, 1919. One of Corning's original Pyrex (borosilicate glass) patents, which describes its chemical composition and physical properties.

US Patent 1,304,623: Sodium aluminosilicate glass article strengthened by a surface compressive stress layer by David Boyd, Corning, December 11, 1973. Corning's patent for the super-strong "Gorilla glass" that Apple used to such great effect in its smartphones and tablets.

US Patent 20160368777: Water solvated glass/amorphous solid ionic conductors by John B. Goodenough et al, December 22, 2016. One of the 20th-century's most innovative chemists proposes a completely new kind of battery based on glass.

Please do NOT copy our articles onto blogs and other websites

Articles from this website are registered at the US Copyright Office. Copying or otherwise using registered works without permission, removing this or other copyright notices, and/or infringing related rights could make you liable to severe civil or criminal penalties.

Text copyright © Chris Woodford 2007, 2021. All rights reserved. Full copyright notice and terms of use.

PYREX® is a registered trademark of Corning Incorporated.

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by Chris Woodford. Last updated: January 19, 2021. Now you see it, now you don't. Glass is a bit of a riddle. It's hard enough to protect us, but it shatters with incredible ease. It's made from opaque sand, yet it's completely transparent. And, perhaps most surprisingly of all, it behaves like a solid material...

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Plastic Bottle Manufacturing- Thomas.net 

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Plastic Bottle Manufacturing- Thomas.net 

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Polyethylene Terephthalate water bottles

The plastic water bottle manufacturing process takes place in stages. Typically, the plastic bottles used to hold potable water and other drinks are made from polyethylene terephthalate (PET), because the material is both strong and light. To understand the manufacturing process it's helpful to first examine the composition of PET and how this affects plastic bottles.

PET (Polyethylene Terephthalate) Water Bottles

Polyethylene Terephthalate (or PET, as it is commonly referred to) is a thermoplastic polymer that can be either opaque or transparent, depending on the exact material composition. As with most plastics, PET is produced from petroleum hydrocarbons, through a reaction between ethylene glycol and terephthalic acid. To produce plastic bottles, the PET is first polymerized to create long molecular chains.

Polymerization itself can be a complicated process, and accounts for many of the inconsistencies between one batch of manufactured PET and another. Typically, two kinds of impurities are produced during polymerization: diethylene glycol and acetaldehyde. Although diethylene glycol is generally not produced in high-enough amounts to affect PET, acetaldehyde can not only be produced during polymerization but also during the bottle manufacturing process. A large amount of acetaldehyde in PET used for bottle manufacturing can give the beverage inside an odd taste.

Once the plastic itself has been manufactured, the bottle manufacturing process can begin. To ensure that the PET is appropriate for use, numerous tests are done post-manufacturing to check that the bottles are impermeable by carbon dioxide (which is important for bottles that carry soda). Other factors, such as transparency, gloss, shatter resistance, thickness and pressure resistance, are also carefully monitored.

Plastic Water Bottle Manufacturing Process

The first stage in bottle manufacturing is stretch blow molding. The PET is heated and placed in a mold, where it assumes the shape of a long, thin tube (the process by which the plastic is forced into the mold is called injection molding). The tube of PET, now called a parison, is then transferred into a second, bottle-shaped mold. A thin steel rod, called a mandrel, is slid inside the parison where it fills the parison with highly pressurized air, and stretch blow molding begins: as a result of the pressurized air, heat and pressure, the parison is blown and stretched into the mold, assuming a bottle shape. To ensure that the bottom of the bottle retains a consistently flat shape, a separate component of plastic is simultaneously joined to the bottle during blow molding.

The mold must be cooled relatively quickly, so that that the newly formed component is set properly. There are several cooling methods, both direct and indirect, that can effectively cool the mold and the plastic. Water can be coursed through pipes surrounding the mold, which indirectly cools the mold and plastic. Direct methods include using pressurized air or carbon dioxide directly on the mold and plastic.

Once the bottle (or, in continuous manufacturing, bottles) has cooled and set, it is ready to be removed from the mold. If a continuous molding process has been used, the bottles will need to be separated by trimming the plastic in between them. If a non-continuous process has been used, sometimes excess plastic can seep through the mold during manufacturing and will require trimming. After removing the bottle from the mold and removing excess plastic, the bottles are ready for transportation.

More from Materials Handling

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The plastic water bottle manufacturing process takes place in stages. Typically, the plastic bottles used to hold potable water and other drinks are made from polyethylene terephthalate (PET), because the material is both strong and light. To understand the manufacturing process it's helpful to first examine the composition of PET and how this affects plastic bottles.

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The Basics: Polymer Definition and Properties - American Chemistry Council

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The Basics: Polymer Definition and Properties - American Chemistry Council

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Plastics are in products we use every day that help keep us safe. They are in bicycle helmets, child safety seats, and automotive airbags that protect us and the cell phones that connect us. Plastics also help keep the foods we eat and serve to our families safer and fresher than ever before.

Strong, lightweight plastics enable us to live better while contributing to sustainability in many ways-all of which stem from plastics' ability to help us do more with less.

Plastics help us protect the environment by reducing waste, lowering greenhouse gas emissions, and saving energy at home, at work, and on the road. Plastic packaging helps to dramatically extend the shelf life of fresh foods and beverages while allowing us to ship more product with less packaging material-reducing both food and packaging waste.

Plastic insulation, sealants, and other building products are making our homes significantly more energy efficient, while reducing costs for heating and cooling. And lightweight plastics in cars can dramatically increase miles per gallon, saving drivers money at the pump.

Plastics not only help doctors save lives, they protect our loved ones at home, on the road, on the job and at play. And these advanced materials are helping make health care more affordable.

17.5 Billion pounds of waste potentially diverted from landfills annually as result of announced investments in advanced recycling since 2017

10% Reduction in vehicle weight can result in a 6% - 8% increase in that vehicle's fuel economy, according to the Department of Energy.

Explore Chemistries Critical to Plastics

Chemistry in Everyday Products

Related Policies & Regulations

5 Actions Congress Can Take to Accelerate A Circular Economy

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Plastics are in products we use every day that help keep us safe. They are in bicycle helmets, child safety seats, and automotive airbags that protect us and the cell phones that connect us. Plastics also help keep the foods we eat and serve to our families safer and fresher than ever before.

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All About Bags - Paper vs. Plastic Bags 

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All About Bags - Paper vs. Plastic Bags 

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Fiction: Many believe that paper bags are more environmentally friendly than plastic bags because they are made from a renewable resource, can biodegrade, and are recyclable.

Fact: Plastic shopping bags outperform paper bags environmentally - on manufacturing, on reuse, and on solid waste volume and generation.

The Facts

The belief that paper is better than plastic is not based on science or fact. It is based on misconceptions about how plastic bags are made, how landfills work, the incidence of plastic litter, and that non-biodegrading products are bad for the planet.

Numerous life cycle assessments demonstrate that conventional plastic bags are better for the environment than paper bags.

On resource use: plastic bags play an important role in the conservation of the natural gas resources. In Canada plastic bags are made from ethane which is often burned off in the natural gas refining process.

On manufacturing: paper bag manufacture is much more resource-intensive than plastic bag manufacture.

On reuse: it is difficult to reuse paper bags because they tend to tear.

On solid waste: paper bags have much greater mass and weigh five to seven times more than plastic bags so they add five to seven times more tonnage to the waste stream for municipalities to manage. This in turn results in a fivefold to sevenfold increase in greenhouse gas emissions.

More Detail
Every bag, paper, plastic or reusable, has an environmental impact.

The debate over the comparative environmental impacts of paper versus plastic bags has led to a number of life cycle assessment (LCA) studies in Europe and North America (see section onStudies).

The findings of these LCAs support the fact that plastic bags have a smaller environmental impact than paper bags and that plastic bags are a better environmental solution than paper.

1. On Resource Use - Renewable Versus Non-Renewable Resources

Paper Bags and Trees

Paper bags have a much higher global warming potential (GWP).

The manufacture of paper bags is much more resource intensive than plastic consuming larger amounts of energy and water. See below, or the section next section, Paper versus Plastic-The Studies.

Post-consumer recycled paper used to carry heavy items is problematic.

The Liquor Board of Ontario (LCBO) switched to paper bags. They started with 100% recycled paper content but have since discovered that the bags did not perform well, so the recycled paper content was modified. The four bottle bag is made from virgin paper to carry heavy loads. The one and two bottle bags, which carry very little weight, are made with 35-40% recycled paper content.

Plastic Bags and Natural Gas

Plastic bags were invented as an alternative to paper grocery bags in the late 1970s to protect trees and prevent clear-cutting of our forests.

Plastic bags are a by-product of natural gas extraction and provide an environmental solution to the burn off of this gas during the refining process.

The polyethylene material used for conventional plastic shopping bags is made from ethane, which is the strand of natural gas that is burned off during the refining process to lower the BTU value of the gas so that the gas does not burn too hot (so it can be used as fuel in our homes).

Essentially, the strand of ethane gas is conserved, captured and frozen before it can be burned off into the atmosphere.

2. On Manufacturing - Plastic Bag Manufacturing is More Environmentally Friendly

Life Cycle Assessments (LCA's) show that the manufacture of paper grocery bags has a heavier environmental impact than the manufacture of plastic shopping bags.

According to the Scottish government's 2005 Report on Plastic Shopping Bags, the manufacture of paper bags consumes four times more water than the manufacture of plastic bags and paper generates three times more greenhouse gases.

The EcoBilan Carrefour Life Cycle Assessment shows that in their manufacture, paper bags consume 2.2 times more non-renewable energy than the manufacture of plastic bags; paper bag manufacture consumes 4.7 times more water, emits 3.1 more greenhouse gases and 2.7 times more acid gases than the manufacture of plastic bags.

Each study discloses slight differences in results, but all studies agree that paper bags carry a substantial environmental impact in their manufacture that is not seen with plastic bags.

See the section on Plastic versus Paper - The Studies for more detail.

3. On Reuse - Plastic Outperforms Paper

Whatever type of bag is used, the key to reducing its environmental impact is to reuse it as many times as possible.

Paper bags tend to fail on reuse because they tear easily and are not waterproof.

Conventional plastic bags are highly reusable and outperform paper. They are reused as carry bags and as kitchen catchers for garbage and organics, among their many uses.

The Ontario Ministry of the Environment audit data that tracks the province's 50% bag reduction program shows a 59.1% alternate rate for plastic shopping bags. The 2011 LCA by the UK Environment Agency identified a reuse rate of 40.3%.

The 2011 UK Environment Agency study of supermarket carry bags (LCA) found that paper bags contribute three times more to global warming than conventional plastic shopping bags do.¹

4. On Solid Waste - Paper Generates More Waste

The most significant and immediate impact of a switch from plastic shopping bags to paper grocery bags is the additional volume and tonnage that paper adds to the waste stream. This additional volume correlates directly to significant increases in the amount of greenhouse gases emissions produced to transport it.

Paper grocery bags are heavier than plastic bags. The typical plastic shopping bag weighs 6-8 grams; a standard Kraft paper bag weighs 55 grams. This leads to additional waste, waste management and recycling costs.

It takes seven trucks to transport two million paper bags, versus one truck to carry two million plastic bags.

The differences between paper and plastic strongly supports why bans don't work. In 2006, Taiwan rescinded a ban on plastic bags in their fast food sector. The ban led to an increase in the use of paper bags with a resulting massive increase in tonnage, waste management costs and greenhouse gas emissions.

5. On Recycling - Both Bag Types are Highly Recyclable

Paper bags tend to have higher recycling rates than plastic bags.

Canada has, over the past decade and half, developed a highly effective network of plastic bag recyclers across the country - large and small. Some of the larger players are Merlin Plastics in B.C. and Alberta; EFS in Ontario; Gaudreau Environment; and Inteplast in Atlantic Canada.

Recycling rates of plastic bags in Canada are high. The Ontario Ministry of the Environment's 2010 report on the 50% Plastic Bag Reduction Program determined a 36% recycling rate in municipalities recovering bags in the blue box. In B.C. and Alberta over 30% of the bags are recycled. In Quebec, 33% of all plastic shopping bags are recycled. And in Atlantic Canada, which pioneered bag to bag recycling systems working with large grocery retailers, rates are higher: 50% in NS and 57% in PEI.

¹ http://publications.environment-agency.gov.uk/PDF/SCHO0711BUAN-E-E.pdf

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All About Bags - Paper Versus Plastic Bags - Which is More Environmentally Friendly?

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Fiction: Many believe that paper bags are more environmentally friendly than plastic bags because they are made from a renewable resource, can biodegrade, and are recyclable. Fact: Plastic shopping bags outperform paper bags environmentally - on manufacturing, on reuse, and on solid waste volume and generation.

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Which is More Environmentally Friendly: Paper or Plastic? - How Stuff Works

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Which is More Environmentally Friendly: Paper or Plastic? - How Stuff Works

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As you wrap up your weekly grocery shopping and get in line at the supermarket, it's time for yet another difficult choice. The cashier mechanically spouts at you, "Paper or plastic?" referring to what kind of bag you'd prefer. For some people, it's a stressful decision. Convenience is pulling you toward plastic, but a nagging green conscience might automatically pull you toward paper. However, it's raining, and if your paper bags break, it could ruin your purchases. On the other hand, is it selfish to put immediate convenience over the thousands of years it might take for a plastic bag to degrade in a landfill? But, what a minute -- aren't we encouraged to save the trees and avoid overusing paper?

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Consumer consciences aren't the only ones plagued by the "paper or plastic" question. Grocery stores pay less for plastic bags but get pressure from environmental groups to stop offering them. So, retailers and even entire cities are deciding to stop asking the familiar question. Instead, they're making the decision for us. Touting environmental concerns, the grocery store chain Whole Foods stopped giving out plastic bags in 2008. Entire cities like San Francisco and Oakland, have passed measures restricting -- or even banning -- the use of plastic bags in grocery stores.

In response to Oakland's ban, an organization backed by plastic manufacturers is suing the city. The Coalition to Support Plastic Bag Recycling claims that the city failed to do enough research into the repercussions of such a ban. The suit isn't on the grounds that a ban will wreak havoc on plastic profits, but rather on the environment. The coalition claims that plastic is just as green as paper or, perhaps more accurately, paper is just as harmful to the environment as plastic [source: Heredia]. It contends that replacing plastic bags with paper will cause more harm than good to the planet.

So, what's it gonna be: paper or plastic? Both come with distinct disadvantages to the environment, which we lay out next.

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Which is more environmentally friendly: paper or plastic?

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As you wrap­ up your weekly grocery shopping and get in line at the supermarket, it's time for yet another difficult choice. The cashier mechanically spouts at you, "Paper or plastic?" referring to what kind of bag you'd prefer. For some people, it's a stressful decision.

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Plastics are everywhere. While you're reading this article, there are probably numerous plastic items within your reach (your computer, your pen, your phone). A plastic is any material that can be shaped or molded into any form -- some are naturally occurring, but most are man-made.

Plastics are made from oil. Oil is a carbon-rich raw material, and plastics are large carbon-containing compounds. They're large molecules called polymers, which are composed of repeating units of shorter carbon-containing compounds called monomers. Chemists combine various types of monomers in many different arrangements to make an almost infinite variety of plastics with different chemical properties. Most plastic is chemically inert and will not react chemically with other substances -- you can store alcohol, soap, water, acid or gasoline in a plastic container without dissolving the container itself. Plastic can be molded into an almost infinite variety of shapes, so you can find it in toys, cups, bottles, utensils, wiring, cars, even in bubble gum. Plastics have revolutionized the world.

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Because plastic doesn't react chemically with most other substances, it doesn't decay. Therefore, plastic disposal poses a difficult and significant environmental problem. Plastic hangs around in the environment for centuries, so recycling is the best method of disposal. However, new technologies are being developed to make plastic from biological substances like corn oil. These types of plastics would be biodegradable and better for the environment.

In this article, we'll examine the chemistry of plastic, how it's made, how it's used, and how it's disposed of and recycled. We'll also look at some new biologically based plastics and their role in the future of plastic.

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Plastics are everywhere. While you're reading this article, there are probably numerous plastic items within your reach (your computer, your pen, your phone). A plastic is any material that can be shaped or molded into any form -- some are naturally occurring, but most are man-made. Plastics are made from oil.

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What is Crude Oil, Exactly? - The Atlantic

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What is Crude Oil, Exactly? - The Atlantic

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Plastic Bags - Stopwaste.org From Oil to Plastic

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Plastic Bags - Stopwaste.org From Oil to Plastic

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Non-wood Forest Pr           Food and Agriculture Organization of the United Statesoducts -      +

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Non-wood Forest Pr           Food and Agriculture Organization of the United Statesoducts -      +

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Contents - Previous - Next

Utilization of native woody vegetation is important to the livelihood of the people in arid zones. Foodstuffs, tannins and gum, essential oils, pharmaceutical products are only a few of the numerous non-wood products obtained from woody vegetation. Although called minor forest products, they are of vital importance to the people and often constitute an important part of the total forest revenue.

Of the 350,000 plant species that have been described by botanists, only 3,000 are reported to be sources of useful material for people. Less than 100 of these plants are cultivated on a large scale and none are xerophytic. However, the search for native xerophytic plants of economic value has greatly intensified in recent years.

According to the type of their utilization, non-wood products from dry land vegetation can be divided into the following groups: foliage and fruits, tannins, gums and resins, oils and extracts, fibres and medicinal plants. These products are reviewed in the following sections.

The foliage of woody plants is important to arid zone dwellers: that of palms ( Phoenix, Hyphaene, Borassus), for instance, providing raw material for fibres, enclosures, sand-fixing palisades and household articles; that of trees such as Adansonia, Boscia, Cadaba and Balanites providing vitamin-rich food; foliage of Diospyros melanoxylon, Morus alba and Zizyphus mauritiana, raw material for local industry: cigarette making, sericulture and lac respectively.

The utility of foliage in recycling nutrients, providing shade and reducing wind speed should not be forgotten; well-managed stands of appropriate drought-resistant and palatable deep-rooting woody species also provide valuable aerial fodder for long drought periods when surface vegetation disappears.

The production and consumption of fruit in arid zones provides a dietary supplement as well as commercial opportunity. The growing of trees for fruit production encourages the preservation of more or less permanent stands or scattered individual trees in otherwise bare lands. Such trees are often a feature of Sahelian landscapes and form the basis of traditional agroforestry land use systems still practiced in parts of that region.

Tannin is produced from the fruit, bark, leaves and roots of many arid-zone shrubs and trees. the preparation of tannin involves breaking or crushing the tannin-rich material which is then washed and boiled with water. after separation of insolubles, the thick, viscous extract is evaporated leaving crude tannin which can be purified by extraction of the crude portion with an alcohol-ether mixture depositing tannic acid. tannins can be of widely varying chemical structure but are capable of converting the gelatin of hides and pelts into insoluble non-putrefying material, that is, leather. tannins are readily soluble in water or alcohol giving strongly astringent solutions also useful in medicines. they are used with feric salts in compounding inks of greenish-black to bluish-black colours.

The practice of tanning hides and skins is extremely important in arid and semi-arid regions where pastoralism is the main land use and wildlife thrives, if protected or adequately managed. Tanning permits the processing and protection of the locally-produced raw materials adding utility and commercial value to a major byproduct of meat production.

A large number of arid and semi-arid zone species yield tannin in commercial quantities. For example, from the bark: Acacia nilotica, A. cyanophylla, Eucalyptus astringent, Parkia biglobosa; from the fruit: Calotropis procera, A. farnesiana; from the wood: A. polyacantha, Schinopsis lorentzii; from roots: Punica granatum, Zizyphus spina-christi.

The styptic and astringent properties of tannic acid are useful in the treatment of inflammations, skin eruptions and bowel conditions and thus form an important principle in the action of many medicinal products.

Gums are typical products of broadleaved trees and shrubs. they are complex carbohydrate derivatives of a polysaccharide nature and are either soluble in water as in the case of gum arabic or form mucilages by the absorption of large amounts of water (gum tragacanth). their principal use is in foodstuffs by nature of their ability to impart desired qualities to foods by influencing their viscosity, body and texture; most frequently in confectionery food, flavouring and soft drinks. they also have pharmaceutical applications as demulcents, adhesives in pill manufacture and as emulsifying agents. industrial uses are for adhesives, lithography, paints and inks.

Gums are produced from woody plants either naturally from exudations from cracks in the bark or damage to the bark by insects or animals. Gum flow is also artificially induced by incisions in the bark. The viscous, brittle nodule can be removed by hand.

Other gums are gum Karaya from Sterculia urens, S. villosa (India), and S. setigera (Africa); they provide the raw material for emulsifiers, adhesives, fixatives and laxatives. Gum tragacanth from Astragalus spp. of Asia Minor is even more valuable: it is a natural emulsifier in food products such as mayonnaise but is now being replaced, because of its high cost, by synthetic fermentation type products. Gums of commercial interest are also obtainable from the fruit of the carob ( Ceratonia siligua), gum Mesquite ( Prosopis latifolia) and Indian Squill from Urginea indica.

Resins are generally used in adhesives, paper sizing, surfacing, fixtures for perfumes and in medicines. Other resins for religious end uses include: frankicense and myrrh, from the dry-zone species Boswellia spp. and Commiphora spp.

Plants that produce essential oils are very characteristic of dry areas, and some have been used since ancient times in the Mediterranean region where the essences of rosemary ( Rosemarinus officinalis), thyme ( Thymus vulgaris) and lavender ( Lavandula angustifolia) are extracted by steam distillation for perfumery.

In Latin America, Yucca carnerosana, Agave lechuguilla (Figures 8.3 and 8.4) and Agave sisalana are important producers of fibres in dry lands. Agave sisalana, the producer of sisal and a non-wood plant of the Amarillydaceae family, is planted in the dry lands of Brazil at a density of about 5,000 plants per hectare, yielding around 30 leaves per plant per year. The dried sisal fibre, about 6 per cent of the weight of the green leaves, is principally used for the manufacture of baler twine and also rope, cordage and handicrafts (such as macrame). It is also excellent for paper suitable for thin printing papers, cigarette papers, bank notes and teabags. It can be blended with other pulps for newsprint, wrappings and tissue paper.

In India, fibres are produced from the inner bark of the climber Bauhinia vahlii (ropes for domestic purposes); the bark of the shrubby dryland plants Calotropis gigantea, C. procera spp. hamiltonii and Leptadenia pyrotechnica also yield fibres useful for weaving string and nets.

Possibly 80 per cent of the world's rural populations are reliant on medicinal plants to maintain their health and to cure their ailments.

The collection of herbal drugs has long afforded a gainful occupation for many people in the rural areas and the processing of herbal drugs in traditional phytotherapy includes simple operations such as the preparation of powders, pills, lotions, decoctions and liquid extracts.

Contents - Previous - Next

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Contents - Previous - Next Utilization of native woody vegetation is important to the livelihood of the people in arid zones. Foodstuffs, tannins and gum, essential oils, pharmaceutical products are only a few of the numerous non-wood products obtained from woody vegetation.

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Welcome to The Silver Institute Homepage

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Learn more about The Silver Institute, a global organization solely focused on silver.

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Silver Statistics and Information - National Minerals Information Center

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Silver Statistics and Information - National Minerals Information Center

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Silver has been used for thousands of years as ornaments and utensils, for trade, and as the basis for many monetary systems. Of all the metals, pure silver has the whitest color, the highest optical reflectivity, and the highest thermal and electrical conductivity. Also, silver halides are photosensitive. Owing to the above properties, silver has many industrial applications such as in mirrors, electrical and electronic products, and photography, which is the largest single end use of silver. Silver's catalytic properties make it ideal for use as a catalyst in oxidation reactions; for example, the production of formaldehyde from methanol and air by means of silver screens or crystallites containing a minimum 99.95 weight-percent silver.
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Silver has been used for thousands of years as ornaments and utensils, for trade, and as the basis for many monetary systems. Of all the metals, pure silver has the whitest color, the highest optical reflectivity, and the highest thermal and electrical conductivity. Also, silver halides are photosensitive.

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Get access to files anywhere through secure cloud storage and file backup for your photos, videos, files and more with Google Drive.

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Get access to files anywhere through secure cloud storage and file backup for your photos, videos, files and more with Google Drive.

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Get access to files anywhere through secure cloud storage and file backup for your photos, videos, files and more with Google Drive.

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Get access to files anywhere through secure cloud storage and file backup for your photos, videos, files and more with Google Drive.

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Get access to files anywhere through secure cloud storage and file backup for your photos, videos, files and more with Google Drive.

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Get access to files anywhere through secure cloud storage and file backup for your photos, videos, files and more with Google Drive.

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Wood Products in Our Daily Lives - Oregon Forest Resources Institute

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Wood Products in Our Daily Lives - Oregon Forest Resources Institute

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No matter where you are this very moment, chances are there's a product made with wood right within your reach. Oregon dominates U.S. production of softwood lumber and plywood. Today it is also a leader in engineered wood, and home to the first mill in the United States to manufacture structurally certified cross-laminated timber or CLT. This means your house or apartment, or even your office building, could have been built using wood products made right here in the state.

This 90-second animated video looks at wood products. We use trees for all kinds of daily items. Some are pretty obvious; others, not so much. But when you consider that wood is one of our greatest renewable resources, it's probably a good idea to use wood for whatever we can. This video is part of OFRI's Forest Fact Breaks series, which uses bold animated graphics, sound effects and narration to teach about natural resource topics in a fun, easy-to-understand way.

Oregon's wood products industry is a traded sector, with close to 75 percent of all products made here sold outside the state. This generates revenue that supports mill jobs in Oregon timber towns. Here are some of the many different types of products that can be made from trees harvested in Oregon:

,such as utility poles, house logs, fence posts, pilings, treated timbers, cross-arms and railroad ties

,including products such as cabinets, furniture and fencing

,including shipping pallets, pencils and musical instruments

The ultimate green building material

In addition to being beautiful and durable, wood is gaining increasing recognition in the architecture, engineering and construction communities as a green building product with important environmental advantages over other materials.

Wood is derived from a renewable resource and requires less energy and water to produce than other materials. It's also the only major building material that stores carbon, which is removed from the atmosphere as trees grow. Because of this, wood buildings serve as massive carbon storage units, helping offset carbon emissions that are a major contributor to climate change.

This 90-second animated video looks at the environmental advantages of using wood building products. Carbon sequestration? Check. More environmentally friendly manufacturing process? Check. Sourced locally? Check. There's a lot to consider in less than two minutes. This video is part of OFRI's Forest Fact Breaks series, which uses bold animated graphics, sound effects and narration to teach about natural resource topics in a fun, easy-to-understand way.

Learn more about forest products and green building

Here are some of the many different types of products that can be made from trees harvested in Oregon:

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No matter where you are this very moment, chances are there's a product made with wood right within your reach. Oregon dominates U.S. production of softwood lumber and plywood. Today it is also a leader in engineered wood, and home to the first mill in the United States to manufacture structurally certified cross-laminated timber or CLT.

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US Forrest Service - Energy & Forrest Products

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US Forrest Service - Energy & Forrest Products

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Celebrating Great Outdoors Month on the Continental Divide National Scenic Trail

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Learn more about America’s energy sources: fossil, nuclear, renewables and electricity.

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Copper is a well-known element because of its distinctive reddish metallic color and because it occurs in pure form in daily life. Here is a collection of facts about this beautiful transition metal:

Fast Facts: Copper

Essential Copper Facts

Atomic Number: The atomic number for copper is 29, which means every copper atom contains 29 protons.

Symbol: Cu (from Latin: cuprum)

Discovery: Copper has been known since prehistoric time. It has been mined for more than 5000 years. Mankind has used the metal since at least 9000 BC in the Middle East. A copper pendant dated to 8700 BC was found in Iraq. Scientists believe only iron from meteorites and gold were used by people earlier than copper.

Word Origin: Latin cuprum: from the isle of Cyprus, which is famed for its copper mines and Old English coper and copper. The modern name copper first came into use around 1530.

Properties: Copper has a melting point of 1083.4 +/- 0.2°C, boiling point of 2567°C, specific gravity of 8.96 (20°C), with a valence of 1 or 2. Copper is reddish colored and takes a bright metallic luster. It is malleable, ductile, and a good conductor of electricity and heat. It is second only to silver as an electrical conductor.

Uses: Copper is widely used in the electrical industry. In addition to many other uses, copper is used in plumbing and for cookware. Brass and bronze are two important copper alloys. Copper compounds are toxic to invertebrates and are used as algicides and pesticides. Copper compounds are used in analytical chemistry, as in the use of Fehling's solution to test for sugar. American coins contain copper.

Sources: Sometimes copper appears in its native state. It is found in many minerals, including malachite, cuprite, bornite, azurite, and chalcopyrite. Copper ore deposits are known in North America, South America, and Africa. Copper is obtained by smelting, leaching, and electrolysis of the copper sulfides, oxides, and carbonates. Copper is commercially available at a purity of 99.999+ %.

Isotopes: There are 28 known isotopes of copper ranging from Cu-53 to Cu-80. There are two stable isotopes: Cu-63 (69.15% abundance) and Cu-65 (30.85% abundance).

Copper Physical Data

Appearance: Malleable, ductile, reddish-brown metal

Evaporation Heat (kJ/mol): 304.6

Pauling Negativity Number: 1.90

First Ionizing Energy (kJ/mol): 745.0

Lattice Constant (Å): 3.610

Copper Trivia

Copper has been used since ancient times. Historians even call the period of time between the Neolithic and Bronze Ages the Copper Age.

Copper(I) burns blue in a flame test.

Copper(II) burns green in a flame test.

Copper's atomic symbol Cu is derived from the Latin term 'cuprum' meaning 'metal of Cyprus'.

Copper sulfate compounds are used to prevent fungus and algae growth in standing water supplies such as ponds and fountains.

Copper is a red-orange metal that darkens to a brown color as it is exposed to air. If it is exposed to air and water, it will form a verdigris of blue-green.

Copper has an abundance of 80 parts per million in the Earth's crust.

Copper has an abundance of 2.5 x 10⁻⁴ mg/L in sea water.

Copper sheets were added to the bottom of ships to prevent 'biofouling' where seaweed, assorted other greenery and barnacles would cling to ships and slow them down. Today, copper is mixed into the paint used to paint the underside of ships.

Hammond, C. R. (2004). "The Elements", in Handbook of Chemistry and Physics (81st ed.). CRC press. ISBN 0-8493-0485-7. Kim, BE. "Mechanisms for copper acquisition, distribution and regulation." Nat Chem Biol., T. Nevitt, DJ Thiele, National Center for Biotechnology Information, U.S. National Library of Medicine, March 2008, Bethesda MD. Massaro, Edward J., ed. (2002). Handbook of Copper Pharmacology and Toxicology. Humana Press. ISBN 0-89603-943-9. Smith, William F. & Hashemi, Javad (2003). Foundations of Materials Science and Engineering. McGraw-Hill Professional. p. 223. ISBN 0-07-292194-3. Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.

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Copper is a well-known element because of its distinctive reddish metallic color and because it occurs in pure form in daily life. Here is a collection of facts about this beautiful transition metal: Atomic Number: The atomic number for copper is 29, which means every copper atom contains 29 protons.

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If there were ever an element that could have been voted "least likely to succeed," it would be aluminum. Although ancient Persian potters added aluminum to their clay to strengthen their pottery, pure aluminum wasn't discovered until 1825. By then, humans had been using several metals and metal alloys (or mixtures of metal such as bronze) for thousands of years.

Even after its discovery, aluminum seemed destined for obscurity. Chemists could only isolate a few milligrams at a time, and it was so rare that it sat beside gold and silver as a semiprecious metal. Indeed, in 1884, the total U.S. production of aluminum was just 125 pounds (57 kilograms) [source: Alcoa].

Then, in 1886, American Charles Martin Hall and Frenchman Paul L. T. Heroult, working independently, devised a method to extract aluminum from aluminum oxide. The process, a type of electrolytic reduction, required an enormous amount of electrical power, but it produced the silvery-white metal in large quantities. By 1891, production of aluminum had reached well over 300 tons (272 metric tons) [source: Alcoa]. And it was finding its way into a vast array of products, from pots and pans to light bulbs and power lines to cars and motorcycles.

Today, more than a century later, aluminum is the very symbol of ubiquity. Every year, the United States produces more than 5.6 million tons (5.1 million metric tons) [source: International Aluminum Institute]. Much of that aluminum goes into beer and soda cans -- to the tune of 300 million aluminum beverage cans a day, 100 billion a year [source: Can Manufacturers Institute]. Not bad for an element that went undiscovered for such a long time.

In this article, we'll take a closer look at aluminum -- its properties, occurrence and behavior. We'll also examine the life cycle of aluminum, from its production using the Hall-Heroult process to its reincarnation after recycling. And, finally, we'll explore all of the uses for aluminum, including some future uses that may surprise you.

Let's start with the basics: aluminum from a chemist's point of view.

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If there were ever an element that could have been voted "least likely to succeed," it would be alumin­um. Although ancient Persian potters added aluminum to their clay to strengthen their pottery, pure aluminum wasn't discovered until 1825.

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Nothing has captured the imagination of humans like gold. Egyptians considered the bright yellow metal to be divine and indestructible, a physical manifestation of the sun itself.

The Egyptian word for gold is nub, which survives in the name Nubia, an ancient region in northeast Africa that became a major supplier of the precious metal. Aztecs used the word teocuitlatl -- "excrement of the gods" -- to describe gold. And on the periodic table, gold is represented by the symbol Au, from the Latin aurum, which means "shining dawn." By any name, gold has always been associated with wealth and power.

Greed for gold fueled Spanish colonization of the Americas. And the gold rushes of the 19th century, both in California and Australia, triggered a hunger for gold that has hardly been satiated today.

You might think that the constant searching, digging and panning would have yielded enough gold to line every road in Oz, but you'd be wrong. In all of history, only 161,000 tons (146,057 metric tons) of gold have been mined [source: National Geographic]. Compare that to the 5.6 million tons (5.1 million metric tons) of aluminum produced by the United States -- in a single year [source: International Aluminum Institute].

The rarity of gold, however, is just one reason why people value the metal. Its unique physical and chemical properties also make it useful. A one-ounce piece of gold can be hammered into a sheet five-millionths of an inch thick or drawn out into 50 miles (80 kilometers) of wire [source: Temescu]. And it's chemically inert, which means it won't react easily with other chemicals.

Of course, as Shakespeare once said, "All that glitters is not gold." The shiny wedding band on a bride's finger has its dark underbelly. Gold mining is bad for the environment, producing more waste per ounce than any other metal. More troubling, it's dangerous for the low-wage workers employed around the world to pry the metal from the Earth. Hundreds of miners are killed each year by rockfalls and explosions. Hundreds more are buried alive underground.

Understanding all of these issues is critical to understanding how gold works. On the next few pages, we'll study element number 79 on the periodic table and try to to understand the power it holds over our imaginations. Let's start by considering gold's long history, a journey that will take us from the dawn of civilization to the great gold rushes of the late 19th century.

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­Nothing has captured the imagination of humans like gold. Egyptians considered the bright yellow metal to be divine and indestructible, a physical manifestation of the sun itself. The Egyptian word for gold is nub, which survives in the name Nubia, an ancient region in northeast Africa that became a major supplier of the precious metal.

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When European settlers arrived in North America in the 1600s, they found vast forests stretching from the Atlantic Ocean to the Mississippi River. Nearly 40 percent of the land north of Mexico lay beneath tree cover [source: Maycock]. Canada and Alaska held much of this forestland, but even below the Great Lakes, trees dominated the landscape.

While the primeval forests of the New World presented challenges, they offered a resource -- timber -- that would help the colonies grow and prosper. Wood harvested from forestland provided light and heat. It yielded homes and their furnishings. It became the building block of tools and machines. And it formed the framework of wagon and ship, enabling the efficient transportation of goods both across the country and across the sea.

Now, even though log cabins are a historical footnote and fossil fuels reign supreme, forests and forest products remain critical natural resources. And not just in North America. Approximately 30 percent of the planet's land area is forestland, with Russia and Brazil holding the largest tracts [source: Food and Agricultural Organization of the United Nations]. Globally, the forest industry employs 13 million people and produces 123.6 million cubic feet (3.5 million cubic meters) of roundwood [source: Food and Agriculture Organization of the United Nations].

Like any global enterprise, the timber industry is complex and has spawned its share of idiosyncratic vocabulary and technology. This article will examine the world of trees -- from top to bottom, you might say -- to understand exactly how timber works. We'll focus on the forests of the United States, but the principles of planting, growing and harvesting trees is consistent regardless of location. So too are the major threats, such as deforestation, invasive species and wildfires.

Let's get started with a basic question: What's the difference between forest and timber?

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­When European settlers arrived in North America in the 1600s, they found vast forests stretching from the Atlantic Ocean to the Mississippi River. N­early 40 percent of the land north of Mexico lay beneath tree cover [source: Maycock]. Canada and Alaska held much of this forestland, but even below the Great Lakes, trees dominated the landscape.

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In any conversation about fuel and resource consumption, you're likely to hear at least a passing reference to natural gas. Some argue it could wean the modern world off of its dependence on oil and coal. It burns cleaner than other fuel sources, and is readily available in many locations around the globe.

But what is natural gas, and how does it form? Read on, because understanding the answers to these basic questions can paint a clearer picture of the plusses and minuses of this versatile fuel source.

In its unprocessed form, natural gas is actually a mixture of naturally occurring flammable gases. The mix varies from source to source, but its chief ingredients include methane, butane and propane. Like coal and oil, natural gas can form deep underground. The remains of ancient plants and animals decay under the intense heat and pressure created by the layers of sand, silt, rock and water above them. Over time, this geologic pressure cooker causes the decaying materials' carbon atoms to break down, forming thermogenic natural gas.

Since both natural gas and oil come from the same raw material, deposits of both often appear in the same location. In fact, ancient organic matter becomes one fuel or the other depending on its depth and temperature: Deeper deposits, exposed to more of the Earth's heat and pressure, have much higher concentrations of natural gas.

But natural gas can also form in a much shorter, more immediate period of time. Just ask a livestock farmer - or the U.S. Department of Energy. Either will tell you that organic matter such as animal waste produces significant amounts of gas as it decomposes, thanks to methanogenic organisms: bacteria that eat the waste and produce methane as their own waste product.

This biogenic natural gas (or biogas) formed from the decomposition process presents a tremendous renewable resource. According to a 1998 study by advocacy group Natural Gas Vehicles for America, biogas could account for 6 percent of the natural gas used in the U.S., the equivalent of displacing 10 billion gallons of gasoline use per year as of the study date. Biogas typically contains 20 percent to 30 percent less methane than is found in thermogenic natural gas. But purification can filter and concentrate that methane, making biogenic gas useable for heating and transportation.

Techniques for extracting natural gas vary as much as the processes that create it. Thermogenic gas deposits are mined in much the same way as oil: Deep-drilled wells pump the gas to the surface, where it's purified and stored for transport. For deeper deposits, a controversial process called hydraulic fracturing, or fracking, uses a mix of drilling fluids to break through layers of gas-containing shale. This opens the door to more gas, but critics argue that it can contaminate regional water supplies without careful adherence to safety regulations.

Biogenic natural gas is often collected using enclosed chambers called digesters. These airtight chambers collect biogas from waste placed in them. Biogas from large, well-established landfills can sometimes be mined through shallow wells drilled into the mountains of trash.

However companies choose to collect natural gas, the end result for consumers is the same: This cleaner-burning fuel is becoming more widely available, offering an increasingly attractive option for consumers fed up with rising oil prices and concerned about their impact on the environment.

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In any conversation about fuel and resource consumption, you're likely to hear at least a passing reference to natural gas. Some argue it could wean the modern world off of its dependence on oil and coal. It burns cleaner than other fuel sources, and is readily available in many locations around the globe.

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We really depend on crude oil in modern society, but where exactly does it come from? Oil is made of compressed hydrocarbons, the remains of prehistoric animals and plants placed under extreme pressures and temperatures in the Earth's crust. Hydrocarbons take many forms, including coal, natural gas, crude oil and even diamonds [source: Energy Information Administration].

We can find oil supplies just about everywhere in the world, but some areas are more abundant than others. Countries in the Middle East, including Saudi Arabia, Iraq, Iran and others, have massive supplies of oil and are the world's leading oil exporters.

Other countries have strong supplies, including Russia, Venezuela and even the United States. The oil found in Texas in the early 20th century resulted in a significant economic boom for that region. In fact, North America is currently the world's second-largest oil producer [source: Energy Information Administration].

Groups like OPEC -- the Organization of the Petroleum Exporting Countries -- monitor their oil supply and can ration it out as they see fit, which sways the supply and price of oil. This is what led to the "gas crisis" of the 1970s: the Middle Eastern members of OPEC decided to "punish" Western nations for their support of Israel in the war in which the latter was attacked by Syria and Egypt. They imposed an oil embargo, and the result was a drastic upswing in oil prices. A severe recession ensued where gas prices in the U.S. rose from 30 cents per gallon (about 7 cents per liter) to about $1.20 per gallon (about 32 cents per liter) at the height of the crisis [source: Trumbore]. Geopolitical crisis', especially in volatile places like the Middle East, can have a big effect on gas prices in the United States.

Another thing to remember about crude oil and fossil fuels is that they are a non-renewable source of energy. This means that the world is slowly but surely running out of its supply of oil, and once it's gone, it's gone. After all, we can't wait around another few million years for animals to fossilize and become liquefied, can we?

While it's tough to know just how much oil is left in the world, more and more governments and businesses are looking into sources of renewable energy. This includes sources we can never really run out of, including wind, solar power and even heat from deep inside the Earth's core, just to name a few.

As our crude oil supplies dwindle, we know the short supply will make the demand increase -- and the cost will go along with it.

Up next, we'll examine how oil is traded in commodities markets, and how people make money by betting on its future price.

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The ever-changing price of a barrel of oil has a lot to do with what we pay for gasoline at the pump. But do you know the four major factors that contribute to the price of oil?