Wallace Hume Carothers
Wallace Carothers, born 1896, studied the chemistry of giant molecules, leading to production of the first synthetic rubber made in the U.S. and the production of nylon.
As a young instructor at Harvard University, Carothers was already pursuing research in polymers when DuPont’s Charles Stine recruited him for the fundamental research program that Stine was then organizing. Elmer K. Bolton, Carothers’s immediate boss, asked him to investigate the chemistry of an acetylene polymer that might lead to a synthetic rubber. In April 1930 one of Carothers’s assistants, Arnold M. Collins, isolated a new liquid compound, chloroprene, which spontaneously polymerized to produce a rubberlike solid. The new polymer was similar chemically to natural rubber, which encouraged Bolton to exploit it. Neoprene, as the product was named, was superior to the natural product in some applications and became the first commercially successful, though never inexpensive, specialty rubber.
Soon after this discovery another Carothers associate, Julian W. Hill, created a strong, elastic synthetic fiber while trying to produce superpolymers of high molecular weight by reacting glycols and dibasic acids with strong acids under reduced pressure in a molecular still. The resultant early polyesters, however, were problematic: they had such low melting points and high solubility in dry-cleaning solvents that they were not commercially viable. After a few attempts to solve these problems, Carothers discontinued this line of research.
When Carothers finally renewed work in that area in early 1934, he and his team used amines rather than glycols to produce polyamides rather than polyesters. Polyamides are synthetic proteins and are more stable than polyesters, which are structurally similar to natural fats and oils. Carothers’s group soon discovered an outstanding polyamide fiber. Bolton played a key role in the development of the discovery, later named “nylon.”
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Excerpted with permission, Chemical Heritage Foundation