Hexafluoropropylene copolymerization

Uses. Besides polymerizing TFE to various types of high PTEE homopolymer, TEE is copolymerized with hexafluoropropylene (29), ethylene (30), perfluorinated ether (31), isobutylene (32), propylene (33), and in some cases it is used as a termonomer (34). It is used to prepare low molecular weight polyfluorocarbons (35) and carbonyl fluoride (36), as well as to form PTEE m situ on metal surfaces (37). Hexafluoropropylene [116-15-4] (38,39), perfluorinated ethers, and other oligomers are prepared from TEE. 

Uses. Vinyhdene fluoride is used for the manufacture of PVDF and for copolymerization with many fluorinated monomers. One commercially significant use is the manufacture of high performance fluoroelastomers that include copolymers of VDF with hexafluoropropylene (HFP) (62) or chlorotrifluoroethylene (CTFE) (63) and terpolymers with HEP and tetrafluoroethylene (TEE) (64) (see Elastomers, synthetic-fluorocarbon elastomers). There is intense commercial interest in thermoplastic copolymers of VDE with HEP (65,66), CTEE (67), or TEE (68). Less common are copolymers with trifluoroethene (69), 3,3,3-trifluoro-2-trifluoromethylpropene (70), or hexafluoroacetone (71). Thermoplastic terpolymers of VDE, HEP, and TEE are also of interest as coatings and film. A thermoplastic elastomer that has an elastomeric VDE copolymer chain as backbone and a grafted PVDE side chain has been developed (72). 

The most chemical-resistant plastic commercially available today is tetrafluoroethylene or TFE (Teflon). This thermoplastic is practically unaffected by all alkahes and acids except fluorine and chlorine gas at elevated temperatures and molten metals. It retains its properties up to 260°C (500°F). Chlorotrifluoroethylene or CTFE (Kel-F, Plaskon) also possesses excellent corrosion resistance to almost all acids and alkalies up to 180°C (350°F). A Teflon derivative has been developed from the copolymerization of tetrafluoroethylene and hexafluoropropylene. This resin, FEP, has similar properties to TFE except that it is not recommended for continuous exposures at temperatures above 200°C (400°F). Also, FEP can be extruded on conventional extrusion equipment, while TFE parts must be made by comphcated powder-metallurgy techniques. Another version is poly-vinylidene fluoride, or PVF2 (Kynar), which has excellent resistance to alkahes and acids to 150°C (300°F). It can be extruded. A more recent development is a copolymer of CTFE and ethylene (Halar). This material has excellent resistance to strong inorganic acids, bases, and salts up to 150°C. It also can be extruded. 

The preparation and properties of a novel, commercially viable Li-ion battery based on a gel electrolyte has recently been disclosed by Bellcore (USA) [124]. The technology has, to date, been licensed to six companies and full commercial production is imminent. The polymer membrane is a copolymer based on PVdF copolymerized with hexafluoropropylene (HFP). HFP helps to decrease the crystallinity of the PVdF component, enhancing its ability to absorb liquid. Optimizing the liquid absorption ability, mechanical strength, and processability requires optimized amorphous/crystalline-phase distribution. The PVdF-HFP membrane can absorb plasticizer up to 200 percent of its original volume, especially when a pore former (fumed silica) is added. The liquid electrolyte is typically a solution of LiPF6 in 2 1 ethylene carbonate dimethyl car-... 

For instance, the temperature of the solid-solid transition at room temperature of PTFE is lowered of nearly 40 °C for the random copolymerization of 5% by mol of hexafluoropropylene with tetrafluoroethylene [97,98],... 

Peduoropolyethers, which constitute special class of fluoropolymer, are useful as lubricants,1 elastomers,2 and heat-transfer fluids under demanding conditions. Several commerical products are available, which are generally prepared by ring-opening polymerization of hexafluoropropylene oxide or by the random copolymerization oftetrafluoroethylene and hexafluoropropylene with oxygen under ultraviolet irradiation.3 Direct fluorination of hydrocarbon ethers has been reported4 but must be done very slowly under carefully controlled... 

PDD as well as other dioxoles have been copolymerized with monomers such as vinyl fluoride, vinylidene fluoride, tiifluoroediylene, perfluoroalkylethylenes, chlorotrifluoroethylene, hexafluoropropylene, and perfluorovinyl ethers, some of which contain functional groups. 

The largest proportion of TFE is used for the polymerization into a variety of PITH homopolymers. It is also used as comonomer in the copolymerization with hexaflu-oropropylene, ethylene, perfluorinated ether, and other monomers and also as a comonomer in a variety of terpolymers. Other uses of TFE are to prepare low-molecular-weight polyfluorocarbons, carbonyl fluoride oils, as well as to form PTFE in situ on metal surfaces,13 and in the synthesis of hexafluoropropylene, perfluorinated ethers, and other oligomers.14... 

Commercial products based on copolymers of ethylene and TEE are made by free radical-initiated addition copolymerization.69 Small amounts (1 to 10 mol%) of modifying comonomers are added to eliminate a rapid embrittlement of the product at exposure to elevated temperatures. Examples of the modifying comonomers are perfluorobutyl ethylene, hexafluoropropylene, perfluorovinyl ether, and hexafluoro-isobutylene.70 ETFE copolymers are basically alternating copolymers,70 and in the molecular formula, they are isomeric with polyvinylidene fluoride (PVDF) with a head-to-head, tail-to-tail structure. However, in many important physical properties, the modified ETFE copolymers are superior to PVDF with the exception of the latter s remarkable piezoelectric and pyroelectric characteristics. 

The need for highly fluorinated thermoplastic polymers that, unlike PTFE, could be fabricated by conventional melt-processing methods led to the development of a group of resins that are copolymers of tetrafluoroethylene (TFE) with other perflu-orinated monomers. Commercially, the copolymer of TFE and hexafluoropropylene (HFP) is commonly known as fluorinated ethylene propylene (FEP). Copolymerization of TFE with perfluoropropylvinyl ether (PPVE) leads to PFA resins, and copolymerization of TFE with perfluoromethylvinyl ether (PMVE) produces MFA resins. 

PVDF and PTFE have wide application in industry due to their strength, chemical and wear resistance, and dielectric properties. However, VF2 and TFE may be copolymerized with comonomers such as hexafluoropropylene (HFP) and... 

The perfluorinated structure imparts stability against chlorine and strong caustic soda at high temperatures, copolymerization of tetrafluoroethylene with molecules such as perfluoro-5-butyrolactone and hexafluoropropylene oxide as ... 

Fluorinated ethylene propylene (FEP) is produced by copolymerization of tetrafluoroethylene and hexafluoropropylene, and consists of predominantly linear chains. 

Radiation-induced curing of plastic coatings has been discussed,8 and radiation-induced polymerization in the solid state reported.87 The radiation chemistry of epoxy-containing electron resists88 and polycondensation induced by ionizing radiation in the urea-formaldehyde system88 have been described. Radiation-induced copolymerization of the following pairs of monomers has been achieved ethylene-hexafluoropropylene,80 tetrafluoroethylene-propylene,81 tetrafluoroethylene-hexafluoropropylene,82 hexafluoroacetone-a-olefins,83 MMA-di- and tri-methacrylates,84 styrene-acrylonitrile,85 buta-1,3-diene-acrylonitrile,88 and acenaphthylene-vinylcarbazole.87... 

AHM Ahmed, T.S., DeSimone, J.M., and Roberts, G.W., Copolymerization of vinylidene fluoride with hexafluoropropylene in supercritical carbon dioxide. Macromolecules, 39, 15, 2006. 

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 ... 

Copolymers from tetrafluoroethylene and 40% perfluorovinyl methyl ether are also elastomers (glass-transition temperature — 12°C). The copolymerization is carried out in aqueous emulsion with ammonium perfluoro-octanoate as emulsifier. Vulcanization is possible with hexamethylene diamine via the small amount of perfluoro(4-carboxy methyl butyl vinyl ether) also polymerized into the copolymer. This ether is produced from perfluoroglutaryl fluoride and hexafluoropropylene oxide. 

Fluorinated ethylene propylene Made by copolymerization of tetrafluoroethylene (TFE) and hexafluoropropylene (HFP)... 

The copolymerization reactions of vinylidene fluoride and hexafluoropropylene were carried out in the presence of an organic mono-iodide compound, (CF3)2CFI, or di-iodide-compounds, I (CF2)4l, I(CF2)6l> as chain transfer agents and the following results were obtained. 

Hexafluoropropylene and tetrafluoroethylene are copolymerized, with trichlo-racetyl peroxide as the catalyst, at low temperature (43). Newer catalytic methods, including irradiation, achieve copol5mierization at different temperatures (44,45). Aqueous and nonaqueous dispersion polymerizations appear to be the most convenient routes to commercial production (1,46-50). The polymerization conditions are similar to those of TFE homopolymer dispersion polymerization. The copol5mier of HFP-TFE is a random copolymer, that is, HFP imits add to the growing chains at random intervals. The optimal composition of the copolymer requires that the mechanical properties are retained in the usable range and that the MV is low enough for easy melt processing. 

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