A leader of that effort was Wallace Carothers, a young chemist at E. I. du Pont de Nemours & Company. In 1930 he and his research team created neoprene, a synthetic rubber that was more resistant to corrosive chemicals than vulcanized natural rubber. The team then began trying to develop a synthetic fiber from organic building blocks that would bond in the same way amino acids join up to form the protein molecules in silk. The payoff came in 1934 when one of the researchers dipped a rod into a beaker full of syrupy melt. When he pulled the rod out, a thread of the viscous substance came with it, and the stretching and subsequent curing of the strand transformed it into a substance of remarkable strength and elasticity. This was nylon, soon produced in quantity for stockings, toothbrush bristles, and such wartime uses as parachute cloth, ropes, and reinforcement for tires. Because of its low friction and high resistance to wear, nylon also proved valuable for gears, rollers, fasteners, and zippers.
The menu of valuable polymers continued to grow steadily. Polyethylenes, suitable for making bottles, appeared in 1939. Polyester fibers, destined to be a staple of the apparel industry, arrived in 1941. A vinyl-based transparent film called Saran, useful for wrapping food, was developed in 1943. Dacron, whose applications ranged from upholstery to grafts to repair blood vessels, hit the market in 1953. Lycra spandex fiber that could stretch as much as five times its length without permanent deformation was introduced in 1958. Kevlar, a fiber five times stronger than steel on a density-adjusted basis, was launched in 1973. By 1979 the annual production volume of polymers surpassed that of all metals combined. A famously pithy bit of career advice in The Graduate, a late 1960s film, summed up the situation well: when the hero asks someone about promising fields for employment, he is told simply, "plastics."