How Wallace Carothers Invented Nylon

The foundational 1935 patent for synthetic linear polyamides, the chemical process that created the material we now call nylon.

What it covers

This patent describes the chemical synthesis of high-molecular-weight linear polyamides by heating diamines with dibasic acids. By controlling the polymerization process, the inventor created long-chain molecules that could be drawn into strong, flexible fibers. This process transformed simple chemical building blocks into a material capable of replacing natural silk in textiles and industrial applications.

What it doesn't cover

• —Does not cover non-linear or branched polyamide structures.
• —Does not cover the specific manufacturing machinery used for spinning the fibers.
• —Does not cover the use of polyamides in non-fiber applications like molded plastics.

The clever bit

Carothers discovered that by maintaining a precise stoichiometric balance and removing water during heating, he could force the molecules to link into long, stable chains rather than short, useless clumps.

Why it matters

This patent marks the birth of the synthetic fiber industry. It allowed DuPont to mass-produce nylon, which became a critical material for everything from hosiery to parachutes during World War II.

Real-world examples

• 1.Nylon stockings
• 2.Parachute cords
• 3.Toothbrush bristles
• 4.Fishing line