PTFE

PTFE, or polytetrafluoroethylene, is a synthetic fluoropolymer derived from tetrafluoroethylene. It is renowned for its exceptional chemical resistance, high thermal stability, and very low friction, qualities that enable a wide range of industrial and consumer applications. A common trade name for PTFE is Teflon, originally popularized by DuPont.

PTFE is produced by free-radical polymerization of tetrafluoroethylene. The polymer has an extremely high molecular weight, which prevents melt processing in conventional equipment. As a result, PTFE is typically processed by methods such as paste extrusion, compression molding, or sintering of finely divided powders. Modified fluoropolymers like PFA and FEP offer melt-processable alternatives with similar chemistry.

Key properties of PTFE include outstanding chemical inertness, resisting most solvents, acids, and bases. It retains structural integrity across a wide temperature range, with a melting point around 327°C and continuous-use temperatures typically up to about 250°C in air. PTFE has a very low coefficient of friction and a nonstick surface, along with a low dielectric constant, making it an excellent electrical insulator. However, it is relatively soft and exhibits creep under sustained mechanical loads.

Limitations include its processing challenges, relatively low mechanical strength compared with some plastics, and potential degradation at very high temperatures. PTFE can decompose when heated excessively, releasing toxic and corrosive fumes; safe processing requires appropriate controls. It is also not inherently resistant to prolonged ultraviolet exposure without stabilization.

Applications are broad, including nonstick cookware coatings, corrosion-resistant linings for pipes and chemical equipment, gaskets and seals, bearing surfaces, and electrical insulation for cables and components in aerospace and electronics.

History notes that PTFE was discovered in 1938 by Roy J. Plunkett at DuPont and later commercialized under the Teflon brand.