nylon, synthetic thermoplastic material characterized by strength, elasticity, resistance to abrasion and chemicals, low moisture absorbency, and capacity to be permanently set by heat. After 10 years of research E. I. du Pont de Nemours & Company introduced nylon in 1938 as monofilaments for bristles and in 1940 as multifilament yarn for hosiery. Nylon is now manufactured also in the form of sheets, coatings, and molded plastics and used in a variety of products, including fabrics, surgical sutures, thread, insulating wire coverings, mosquito netting and screening, gears and bearings, rope, and tire cords. There are a variety of nylons, all being polyamides frequently made from diamines and dicarboxylic acids. The most generally useful of these is nylon (66), made from hexamethylene amine and adipic acid.