What polymer is commonly known by the brand name Teflon?

The polymer commonly known by the brand name Teflon is polytetrafluoroethylene, or PTFE.

PTFE is a synthetic fluoropolymer made from repeating tetrafluoroethylene units. Its carbon–fluorine structure makes it highly chemically resistant, water-repellent, electrically insulating, and exceptionally low-friction. Those properties explain its use in nonstick cookware, seals, chemical-processing equipment, laboratory components, and lubricating applications.

Chemist Roy J. Plunkett discovered PTFE accidentally in 1938 while investigating refrigerant gases for DuPont. A gas cylinder appeared empty but was heavier than expected; its interior held a slippery, waxy solid that proved to be the new polymer. The Teflon trademark was registered in 1945.

Teflon is a brand name, not the chemical name for every fluoropolymer coating. PTFE is the best-known Teflon material, although the trademark has also been used for related fluoropolymers. PTFE’s high heat resistance does not mean overheated cookware is harmless: extreme overheating can cause decomposition fumes.