Hexafluoropropylene-vinylidine fluoride

Binder Nomenclature Identification a — Polyvinyl butyral resin — Monsanto Co b — Hexafluoropropylene/vinylidine fluoride 1 2 c - Polyurethane soln system - B.F. Goodrich Co d — Polytrifluorochloroethylene - 3M Co... 

Viton. A trademark of the E.I. duPont de Nemours Co for a series of fluorelastomers based on the co-polymer of vinylidine fluoride and hexafluoropropylene with a repeating structure of [-CF2-CH2-CF2-CF(CF3H white, transparent solid sp grav 1.72—1.86. Resistant to corrosive liqs and chemicals up to 600°F, and useful in continuous service at 400—500°F. The material is resistant to weather, ozone, flame, oils, fuels, lubricants and many solvents According to Refs 2 3, Viton-A is used in many expl formulations developed by the Lawrence Livermore Laboratory, such as LX-04, LX-07, LX-10-0, LX-10-1 and LX-11-0 (see Vol... 

Estane 5702-Fl Viton A BDNPA-F Polyurethane solution system Vinylidine fluoride/hexafluoropropylene copolymer, 60/40 wt % Bis(2,2-dinitropropyl)acetal/bis(2,2-dinitropropyl) formal, 50/50 wt % Tris- -chlorethylphosphate Chlorotrifluoroethylene/vinylidine fluoride copolymer, 3 1 Vinyl chloride/chlorotrifluoroethylene copolymer, 1.5 1 Styrene polymer, 100% Di(2-ethylhexyl)phthalate Bis(2-fluoro-2,2-dinitroethyl)foimal... 

The volume of commercial fluorine containing polymers is not large when compared with other polymers, such as poly(vinyl chloride). Fluoropolymers, however, are required in many important applications. The main monomers are tetrafluoroethylene, trifluorochloroethylene, vinyl fluoride, vinylidine fluoride, and hexafluoropropylene. 

Copolymers of vinylidine fluoride with hexafluoropropylene are prepared in aqueous dispersions using persulfate initiators. Hexafluoropropylene does not homopolymerize but it does copolymerize. This means that its content in the copolymer cannot exceed 50%. Preferred compositions appear to contain about 80% of vinylidine fluoride. The crosslinking reactions with diamines are not completely understood. It is believed that the reaction takes place in two steps. In the first one, a dehydrofluorination occurs ... 

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