Why is nylon not a natural polymer compound?

Nylon, transliteration of English name nylon. In carothers, polyhexamethylenediamine, namely nylon 66, formed by the condensation reaction of hexamethylenediamine and adipic acid at 1937, is the earliest commercialized polymer synthetic fiber, and the first pair of nylon stockings was made at 1937. Dupont Company immediately obtained the patent right on September 1938 with the trade name of "Nylon". Because nylon material is light and tough, it was later used as a substitute material for silk to make parachutes urgently needed by the allied forces, which greatly enhanced the strength of the allied airborne troops.

Nylon is a polymer product synthesized by chemical synthesis reaction, so it is not a natural polymer compound.