Fluorocarbon epoxides

The classic process involves the chemistry of fluorocarbon epoxides. Its initial step is a catalytic oxidation of HFP into a fluoroepoxide. The fluoroepoxide is then reacted with a metal fluoride to obtain an acid fluoride, which is then pyrolyzed over calcium carbonate at 250°C (482°F) to obtain propylvinyl ether (PVE).36-37... 

The bis(tetiafluoroethyl) ethers obtained by reacting polyethyleneglycol with tetrafluoroethylene have useful surface activity. 1 The preparation of aminoacetals of the type (CF3)2C C(NMes)OAr, by the successive reaction of the sodium salt of a phenol and then of dimethylamine with perfluoroisobutene has been described i in the compound (CFs)2C C(NMea)OMe, the CF3 groups are equivalent on the n.m.r. timescale at low temperatures, indicating a low barrier to rotation about the C=C bond. A number of fluorocarbon epoxides have been prepared... 

Silicones, fluorocarbons, epoxides, polyxylylenes, polyurethanes, polyimides. 

Fluorocarbon-modified HEC is a more potent viscosifier than hydrophobe-modified HEC because fluorocarbons can micellize at lower concentrations than alkyl hydrophobes. Moreover, the fluorocarbon epoxide synthetic route gives fluorocarbon modified HEC polymers with a better balance of solubility and viscosification efficiency than does the fluorocarbon tosylate method. 

The reaction of OF2 and various unsaturated fluorocarbons has been examined (35,36) and it is claimed that OF2 can be used to chain-extend fluoropolyenes, convert functional perfluorovinyl groups to acyl fluorides and/or epoxide groups, and act as a monomer for an addition-type copolymerization with diolefins. 

As a resirlt of the differences in polarity between the carbon fluorine and the carbon-hydrogen bond, fluorocarbon chemistry is wrought with more differences than similarities to hydrocarbon chemistry despite their similarities in van der Waal s radii (1.20 vs. 1.35 A). A great body of chemistry for the functionalized fluorocarbons has been developed in the areas of perfluoroalkenes, halofluoroalkanes, ethers, epoxides, peroxides, ketones, acids, and esters. 

Fig. 20. Dq>endence of dielectric strength Ebf on the apparent density for rigid oligomeric foams epoxide foamed by fluorocarbon -PE-8 (x), PE-9 ( ) polyurethanes foamed by carbon dioxide - PPU-307 (a), ffU-305 A (o)1 O...

This group, commonly called epoxy, characterizes the epoxy resins. Epichlorohydrin and ethylene oxide are well-known epoxides. The compounds are also used in certain types of cellulose derivatives and fluorocarbons. 

Epoxides - Organic compounds containing three-membered cyclic group(s) in which two carbon atoms are linked with an oxygen atom as in an ether. This group is called an epoxy group and is quite reactive, allowing the use of epoxides as intermediates in preparation of certain fluorocarbons and cellulose derivatives and as monomers in preparation of epoxy resins. 

An enantioselective epoxidation in a fluorous biphasic system was reported in 1998. The fluorous manganese complex 17 was tested for the enantioselective epoxidation of alkenes in the presence of molecular oxygen and sacrificial aldehydes. The characteristic ability of fluorocarbons to dissolve large quantities of... 

The approach offluorous biphase systems utilizes the low miscibihties of fluorocarbons with most organic solvents, which allow easy separation of a catalyst soluble in the fluorocarbon phase from the product soluble in the organic phase . The fluorocarbon-soluble cobalt complex of the tetraarylporphyiin Ugand in Figure 38 catalyzes the epoxidation of alkenes... 

Recently, Hogen-Esch [26] has modified HEC with fluorocarbon tosylates and epoxides (Eq. 1.4, 1.5). 

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