Nylon — The First Fully Synthetic Fiber from Coal, Air, and Water

On February 28, 1935, Wallace Hume Carothers at DuPont's research laboratory in Wilmington, Delaware, synthesized nylon 6,6 — the first fiber made entirely from petrochemical building blocks with no natural polymer precursor. Unlike viscose rayon (which dissolves and regenerates natural cellulose), nylon is built from scratch: two small molecules — hexamethylenediamine and adipic acid — are reacted together, and the resulting polymer is melt-spun into filaments. The raw materials ultimately derive from coal, air (nitrogen), and water.

Nylon is a polyamide — a polymer whose repeating units are linked by amide bonds (-CO-NH-), the same bond that connects amino acids in proteins like silk fibroin and wool keratin. This is not coincidence: Carothers deliberately set out to create a synthetic analog of silk by mimicking nature's chemistry with industrial feedstocks. The '6,6' designation means both monomers contribute six carbon atoms each to the repeating unit.

DuPont introduced nylon commercially in 1938 (toothbrush bristles) and 1940 (women's stockings). On 'Nylon Day' — May 15, 1940 — four million pairs of nylon stockings sold in four days. During World War II, nylon was diverted entirely to military production: parachutes, tire cord, ropes, and tent fabric. Carothers himself did not live to see nylon's triumph — suffering from severe depression, he died by suicide on April 29, 1937, at age 41. Nylon proved that useful materials could be designed at the molecular level, launching the age of synthetic polymers that now produce over 70 million tonnes of fiber annually.