PTFE is produced by free-radical polymerization of tetrafluoroethylene. The net equation is
n F2C=CF2 → −(F2C−CF2)n−
Because tetrafluoroethylene can explosively decompose to tetrafluoromethane and carbon, special apparatus is required for the polymerization to prevent hot spots that might initiate this dangerous side reaction. The process is typically initiated with persulfate, which homolyzes to generate sulfate radicals:
[O3SO−OSO3]2− ⇌ 2 SO4•−
The resulting polymer is terminated with sulfate ester groups, which can be hydrolyzed to give OH end-groups.
Because PTFE is poorly soluble in almost all solvents, the polymerization is conducted as an emulsion in water. This process gives a suspension of polymer particles. Alternatively, the polymerization is conducted using a surfactant such as PFOS.