The first polyamide plastic was prepared in 1934 by the American chemist W. H. Carothers, although it was not until 1937 that production was started commercially. The new plastic was called nylon. The chief raw materials used in the production of nylon are benzene and butadiene (CH2=CH-CH=CH2). Various intermediates, particularly caprolactam, are produced before the final product is obtained. Polyamide, or nylon, molecules have repeating units of the following structure: -(CH2)nCONH(CH2) HNOC-
The subscript letters m and n represent numbers, the values of which depend on the particular poly- amide; in Nylon 66, for example, n is 4 and m is 6. Polyamides are chiefly used for making molded articles (including household fixtures and fittings) and textiles such as garments.