any of a class of elastomers, or rubberlike synthetic organic compounds of high molecular weight (polymers), made by chemical combination of the simpler compound 2-chloro-1,3-butadiene (chloroprene); it is used in numerous products, such as shoe soles, hoses, and adhesives, that require better resistance than natural rubber to oil, solvents, heat, and weathering.

The neoprenes, discovered in 1931, were the first synthetic rubbers developed in the United States. They are ordinarily vulcanized by using magnesium oxide or zinc oxide, although sulfur is sometimes employed. The products are too expensive for use in making tires, but their resistance to chemicals and to oxidation makes them valuable in specialized applications. See also Elastomers (natural and synthetic rubber) (elastomer).