Perfluorovinyl ether

Perfluorinated ethylene—propylene copolymers, Tetrafluoroethylene—ethylene copolymers, Tetrafluoroethylene—perfluorovinyl ether copolymers, Poly(vinyl fluoride),... 

Tetrafluoroethylene [116-14-3] and perfluorovinyl ether are copolymerized in aqueous (1,2) or nonaqueous (3) media. The polymer is separated and converted into various forms, such as extmded cubes, powders, beads, or dispersions. This family of products is manufactured by Du Pont, Daikin, and Hoechst and sold under the trade names of Teflon PEA, Neoflon AP, and Hostaflon TEA, respectively. 

Preparation. The preparation of tetrafluoroethylene has been described previously. Perfluorovinyl ethers (4—7) are prepared by the following steps. Hexafluoropropylene [116-15-4] (HEP) is oxidized to an epoxide HEPO [428-59-1] (5) which, on reaction with perfluorinated acyl fluorides, gives an alkoxyacyl fluoride. 

The perfluorovinyl ether comonomer used for PEA is expensive, as is PEA. Most PEA grades are sold as extmded, translucent cubes in various colors at 47.9—60.3/kg. Some PEA types are also marketed in nonextmded forms. 

Eor curing copolymers of tetrafluoroethylene and perfluorovinyl ether, addition of ca 4% TAG has been proposed (118). TEE—propylene copolymers have been cured by TAG and organic peroxide (119). Copolymers of TEE-propylene-vinyUdene fluoride are cured with TAG by heating at 200°C. 

The nucleophilic reaction of bromotrifluoroethene with alkoxides yields not only the expected addition and addition-elimination products but also a product from a bromophilic reaction of the carbanion intermediate [6] (equation 3) Similar are the reactions of sodium phenoxide with perfluorovinyl ethers in the presence of hexachloroethane or selected vicinal dibromoperfluoroalkanes The intermediate carbanion is trapped in high yield by these sources of Cl or Br, which suggests a... 

Perfluorinated polymers, 18 288-353. See also Perfluorinated ethylene-propylene (FEP) copolymers poly tetr afluoroethylene, 18 288—306 tetrafluoroethylene-ethylene copolymers, 18 316-329 tetrafluoroethylene-perfluorodioxole copolymers, 18 339-342 tetrafluoroethylene-perfluorovinyl ether, 18 329-339... 

Perfluorotributylamine, as blood substitute, 4 112-113 Perfluorovinyl ethers, preparation of, 18 329-330... 

Teflon HP Plus copolymers, 18 331 in lotus effect surfaces, 22 117 Teflon PFA. See also Tetrafluoroethylene-perfluorovinyl ether applications of, 18 338-339 chemical properties of, 18 332-333 economic aspects of, 18 338 electrical properties of, 18 334 health and safety factors related to, 18 338... 

Tetrafluoroethylene-(TFE)-perfluoropropyl vinyl ether copolymers, 7 641 Tetrafluoroethylene-perfluorovinyl ether, 48 329-339. See also Teflon PFA copolymerization of, 48 330—331 Tetrafluoroethylene-perfluorodioxole copolymers, 48 339—342. See also Teflon AF copolymers applications of, 48 342 economic aspects of, 48 341—342 health and safety factors related to, 48 342 monomer preparation, 48 339 synthesis of, 48 339-340 Tetrafluoroethylene (TFE) copolymerization with... 

Nucleophilic fluoroalkylation in the anomeric position has been performed with trifluorochloroethylene, or with perfluorovinyl ethers." The compound obtained with trifluorochloroethylene is an irreversible inhibitor of a-glycosidases (Figure 6.44). " Trifluoromethylzinc bromide can be used to perform the difluor-omethylation of hydroxyls in various positions, probably through a carbenic mechanism. 

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. 

Reaction of 2,2-difluoro-2-(methoxycarbonyl)acetyl chloride (3) with potassium fluoride affords 2,2-difluoro-2-(methoxycarbonyl)acetyl fluoride (4) in 90 % yield, which is one of the precursors for the preparation of perfluorovinyl ethers containing a carboxylic group.30... 

Hostaflon TFA - [FLUORINECOMPOUNDS,ORGANIC - TETRAFLUOROETHYLENE-PERFLUOROVINYL ETHER COPOLYMERS] (Vol 11)... 

D. Fluorocarbon Polymers. Four different fluorocarbons account for the bulk of the laboratory applications polytetrafluoroethylene, Teflon PTFE po-ly(chlorotrifluoroethylene), KEL-F tetrafluoroethylene-hexafluoropropylene copolymer, Teflon FEP and tetrafluoroethylene-perfluorovinyl ether copolymer, PFA. These polymers are inert with most chemicals and solvents at room temperature and exceptionally inert with oxidizing agents. They also have an exceptional resistance to temperature extremes. However, they are decomposed by liquid alkali metals, solutions of these metals in liquid ammonia, and carban-ion reagents such as butyllithium. Teflon retains some of its compliance at liquid hydrogen temperature. The maximum temperature which is recommended for continuous service is 260°C for Teflon PTFE and PFA, and about 200°C for Kel-F and Teflon FEP. 

This similarity in reactivities probably derives from a fortuitous cancellation of substituent effects in 11. Fluorination increases chain stiffness and creates an unfavorable polarity mismatch between an electrophilic radical and an electron-poor double bond, but this is offset by the significant decrease of 7r-bond energy in 11. The vinyl ether 12 analog cyclizes about seven times faster than 11, which is consistent with the known lower 7r-bond energy and higher free-radical reactivity of perfluorovinyl ethers vs perfluoroalkenes [142]. 

Hexafluoropropylene does not polymerize into a homopolymer easily therefore, it can be stored as a liquid. Flowever, it forms industrially useful copolymers and terpolymers with other fluorinated monomers. Oxidation of F1FP yields an intermediate for a number of perfluoroalkyl perfluorovinyl ethers.30... 

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. 

Perfluoro elastomers having improved low-temperature properties were prepared by Grootaert [4] and consisted of TFE-HFP-perfluorocyanopropyl perfluorovinyl ether, (111), 65.0 34.2 0.8, respectively. 

Photoresist compositions consisting of pentafluoromethylvinyl carbonate derivatives, (II), were prepared by Yoon [2] and used in photosensitive polymers for exposure to light sources having a dominant wavelength of less than 157 nm. Perfluorovinyl ether, (III), monomers were prepared by DiPietro [3] and used in lithographic photoresist polymer compositions. 

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