1935

Nylon

Elmer Keiser Bolton (1886–1968), Wallace Hume Carothers (1896–1937), Julian Werner Hill (1904–1996)

Modern polymer chemistry began with the discovery of polyethylene in the U.K. and nylon in the U.S. The natural polymer fibers (such as cotton and wool) clearly showed that there was a lot of potential in the area that no one knew how to realize. Bakelite had been a great success, but it could never be drawn out into threads. American chemist Wallace Hume Carothers, who headed a polymer lab at DuPont, had discovered a useful synthetic rubber (neoprene) and several polymers that could be spun into thread, but these had some severe disadvantages: they dissolved in dry-cleaning solution, for starters.

Carothers’s team turned to different projects, but news of other chemists’ polyethylene work motivated the director of DuPont’s chemistry department, American chemist Elmer Keiser Bolton, to ask Carothers to try again. They used the same thread-drawing techniques that their team member American chemist Julian Werner Hill had tried before, this time using amide bonds between the polymer constituents, and a whole new class of materials emerged. Varying the chain lengths of the acid and amine components was a key part of the research, and when both the acid and amine chains were six carbons long, the material known as nylon was produced—and in only three years, the first industrial plant producing spun nylon thread was in operation. Like many other discoveries of the late 1930s, it spent its early years contributing to the World War II effort (as a substitute for silk in parachutes, among many other things). It was strong, hard to break or tear, and resistant to heat and solvents (but not strong acid). It’s still the most common synthetic fiber in textiles, and also used in fasteners, machine parts, and cookware.

Carothers, sadly, did not live to see it. He had always been prone to depression, and eventually committed suicide—a great loss for the scientific community, even if he was unable (as he said) to value his own achievements. He had an eye for talent, too, hiring the Nobel Prize–winner Paul Flory, who became one of the great polymer chemists of twentieth century.

During World War II, salvaged nylon stockings were repurposed into parachutes for army fliers, tow ropes for glider planes, and other war material.