Tetrafluoroethylene-perfluoropropylene

Major polymer applications wire coating, data transmission cable, lined pipes, components for valves and pumps 

Important processing methods injection molding, wire coating, extrusion 

Typical fillers graphite, glass fiber, bronze 

Special considerations creep and wear resistance are minimized by addition of fillers 

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Tetrafluoroethylene-perfluoropropylene (FEP) resembles PTFE in its properties, but can be processed as a thermoplastic polymer. 

The reaction of cellulose with tetrafluoroethylene, perfluoropropylene (66), and perfluoroisobutylene (67) has also b studied. 

Tetrafluoroethylene of purity suitable for granular or dispersion polymerizations is acceptable for copolymerization with ethylene. Polymerization-grade ethylene is suitable for copolymerization with tetrafluoroethylene. Modifying termonomers, eg, perfluorobutylethylene and perfluoropropylene, are incorporated by free-radical polymerization. 

Radiation-induced grafting29 was used for the preparation of low-cost polyelectrolyte membranes needed for fuel-cells30. Guzman-Garcia and coworkers29 studied the grafting of poly(styrenesulphonic acid)on polystyrene on a copolymer of poly(tetrafluoroethylene) with polystyrene, and with a copolymer of poly(tetrafluoroethylene) with poly(perfluoropropylene). 

Cellulose does not react with tetrafluoroethylene and perfluoropropylene in the absence of a catalyst, but it does with perfluoroisobutylene, in which the specific properties of fluorolefins are especially pronounced due to the electron-accepting effect of tl two unsym-metrically arranged trifluoromethyl groups, even in the absence of a catalyst. The fluorolefins under study can be arranged in the following... 

Application of diallyl terephthalate as an accelerator for curing fluorinated polymers such as a terpolymer of tetrafluoroethylene, vinylidene fluoride, and perfluoropropylene [123]. 

As has been indicated earlier, an organic halide such as carbon tetrachloride can react with a ditin to produce the triorganotin halide with the aid of a free radical initiator such as benzoyl peroxide (266, 267). Again with ultraviolet catalysis, hexamethylditin adds to tetrafluoroethylene to produce 1,2-bis-(trimethylstannyl)tetrafluoroethane (282). A similar reaction occurs with perfluoropropylene (282a). 

A family of copolymers containing TFE and perfluoromethyl vinyl ether modified with PPVE referred to as MFA is produced by Ausimont (24). The relatively small pendant group —0—CF3 seems to have a similar effect on the crystallinity reduction as is exhibited by —CF3 in FEP (perfluoropropylene-tetrafluoroethylene copolymer) however, the higher reactivity of perfiuoromethyl vinyl ether than that of HFP makes the polymerization process more efficient. The performance characteristics are described in References 11 and 25. 

Similar mechanism of radiation degradation of poly(tetrafluoroethylene-co-perfluoropropylene) (FEP) was reported based on the NMR spectra [OlGl]. As it is shown in Fig. 44, some of segments disappear, especially the units centered on tertiary carbons, but others are reattached onto molecules building up highly branched structures. 

The preparation of a new class of processable heavily fluorinated aciylic resins with veiy low dielectric constants is described. The title compounds 2 and 5 were prepared through the condensation of the respective aicohols 1 and 4 with aciyloyl chloride. Unlike tetrafluoroethylene, monomers 2 and 5 are ea to process into polymers under normal conditions due to their liquid or semisolid nature. Radical polymerization of the title compounds with a trace amount of azobisisobutyronitrile or methyl ethyl ketone peroxide at 85-100 leads to homopolymers 3 and 6 and copolymer 7. All polymers exhibit dielectric constants around 2.10-2.24 over a frequency region of 500 MHz to 18.5 GHz the variation of dielectric constant values over the measured frequency region is within 0.03 for each polymer. These values are very close to the minimum known dielectric constants of 2.0-2.08 for poly(tetrafluoroeth-ylene) and 1.89-1.93 for a terpolymer of 2,2-bis-(trifluoromethyl)-4,5-difluoro-1,3-dioxole 8, perfluoropropylene and tetrafluoroethylene 9. The dielectric constants for poly(tetraf1uoroethylene) measured with the same method are observed to be around 1.96-1.99 in order to validate the accuracy of our measurement. 

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