FEP is produced by free-radical polymerization of mixtures of tetrafluoroethylene and hexafluoropropylene. Ethylene tetrafluoroethylene (ETFE) is a fluorine-based plastic. An important application of this reaction is the production of tetrafluoroethylene (TFE), precursor to Teflon. PTFE is produced by free-radical polymerization of tetrafluoroethylene. Octafluorocyclobutane is produced by the dimerization of tetrafluoroethylene and the reductive coupling of 1,2-dichloro-1,1,2,2-tetrafluoroethane. In the predominant application, chloroform is required for the production of tetrafluoroethylene, precursor to teflon. Chlorodifluoromethane is then converted into tetrafluoroethylene, the main precursor to Teflon. Tetrafluoroethylene (TFE) is a fluorocarbon with the chemical formula CF. This difference is significant because difluorocarbene is a precursor to tetrafluoroethylene. Fluorinated ethylene propylene (FEP) is a copolymer of hexafluoropropylene and tetrafluoroethylene. Examples of such ligands are TCNE, tetrafluoroethylene, maleic anhydride, esters of fumaric acid. An important application of R-22 is as a precursor to tetrafluoroethylene. The canopy over the Western and Eastern stands is covered with translucent ethylene tetrafluoroethylene. R-22 is a versatile intermediate in industrial organofluorine chemistry, e.g. as a precursor to tetrafluoroethylene. PCTFE is a homopolymer of chlorotrifluoroethylene (CTFE), whereas PTFE is a homopolymer of tetrafluoroethylene.