Synthetic silks

The new fibers were scientifically interesting—and they eventually laid the foundation for the synthetic textile industry—but at the time they seemed practically worthless. The first polyester fibers resembled those produced by the lowly silk worm, but Carothers did not think that the discovery would be commercially valuable. The polymer chains made in Hill s molecular still were still not long enough to make robust fibers. The filaments melted at such a low temperature and were so soluble that they could not be ironed or washed in dry cleaning fluid or hot water. Carothers knew he would have to make longer polymers if he hoped to make a marketable fiber. Instead, Carothers dramatized the romance of Hill s discovery by quoting the seventeenth-century microscopist, Robert Hooke, who had dreamed of making synthetic silk even better than that Excrement made by silk worms. 

Anonymous. Chemists Produce Synthetic Silk. The New York Times. Sept. 2, 1931. 

The next inventor to make a mark was Louis Marie Hilaire Bernigaud, the Comte de Chardonnet. He was searching for a way to make a synthetic silk (as we describe in the Polymer Milestone below). Hopefully,... 

The discovery of nylon is one example. In 1928, E.l. DuPont de Nemours and Company appointed a young, 32-year-old chemist from Harvard, Wallace Carothers, as the director of its new research center. The goal was to create artificial fibers similar to cellulose and silk. In 1930, Julian Hill, a member of Carothers team, dipped a hot glass rod in a mixture of solutions and unexpectedly pulled out long fibers such as the one shown in Figure 1-14. Carothers pursued the development of these fibers as a synthetic silk that could withstand high temperatures and eventually developed nylon in 1934. Nylon s first use was in a toothbrush with nylon bristles. During World War 11, nylon was used as a replacement for silk in parachutes. Nylon is used extensively today in textiles and some kinds of plastics. 

Chemically modified cellulose in the form of cellulose nitrate or nitrocellulose was made and tested for commercial applications in Britain in the 1855-1860 period without much success. The discovery by Hyatt, in 1863, that cellulose nitrate could be plasticized with camphor to give moldability to the blend, made this material much more useful. By 1870, celluloid (plasticized cellulose nitrate) was being produced into a variety of commercial products such as billiard balls, decorative boxes, and combs. Nitrocellulose was also soluble in organic solvents, unlike cellulose, and so could be applied to surfaces in solution to form a coating, as in airplane dopes and automobile lacquers. It could also be solution spun into fibers (synthetic silk) and formed into photographic film, or used as a laminating layer in early auto safety glass. It was also used as an explosive. The hazard introduced to many of these uses of nitrocellulose by its extremely flammable nature resulted in an interest to discover other cellulose derivatives that could still be easily formed, like nitrocellulose, but without its extreme fire hazard. 

Nylon was designed to be a synthetic silk, (a) The average molar mass of a batch of nylon 66 is 12,000 g/mol. How many monomer units are there in this sample (b) Which part of nylon s structure is similar to a polypeptide s structure (c) How many different tripeptides (made up of three amino acids) can be formed from the amino acids alanine (Ala), glycine (Gly), and serine (Ser), which account for most of the amino acids in silk ... 

Nylon Parachutes, synthetic silk, clothing Very tough, withstands hot water... 

When the boss came back, they told him, and nylon was developed—over a period of 10 years—into a silk-like material. Advertised at the 1939 New York World s Fair as synthetic silk made from coal, air, and water, its application in hosiery for women was demonstrated by a model in a giant test tube. The material was an instant success. Reportedly four million pairs of nylon stockings sold in a few hours in the first New York City sale, but almost immediately sales were restricted and the material commandeered for parachutes. William Carothers did not live to see the success. He died by his own hand in a Philadelphia hotel in 1937. 

Werke 8/45 -12/46 Doeberitz, Gabel, Premnitz Synthetic Silk, Sulfuric Acid 15.0 70%... 

Nylon was designed to be a synthetic silk, (a) The "L ARiS average molar mass of a batch of nylon 66 is... 

Spider-web silk is ca. five times stronger than steel by weight, and almost as elastic as nylon. Fibers comprised of the synthetic silk were demonstrated to be stronger than Kevlar, and may be useful for biomedical applications such as artificial tendons and ligaments and surgery sutures, as well as lightweight body armor for military applications. 

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