Hexafluoropropylene epoxide

HFP is thermally stable up to 400°C to SOOT (752°F to 932°F). At about 600°C (1112°F) under vacuum, HFP decomposes and produces octafluoro-2-butene (CF3=CFCp3) and octafluoroisobutylene [44]. Under basic conditions, hydrogen peroxide reacts with HFP to form hexafluoropropylene epoxide, which is an intermediate in the preparation of perfluoroalkylvinyl ethers [45,46]. Hexafluoropropylene readily... 

Hydrolysis of each acid fluoride fraction and redistillation of the carboxylic acids allowed separation of mono- from dicarboxylic acids (Table III). Thus, the 1 1 dicarboxylic acid and the monocarboxylic acid formed from three molecules of hexafluoropropylene epoxide were isolated from the 1 1 oligomer acid fluoride fraction shown in Table II. The acids were converted to acid chlorides in high yields (about 90%) by prolonged refluxing with thionyl chloride (Table IV). A trace of pyridine was added as a catalyst. 

Tetrafluorothiirane, 6 (n = 1), lacks a sulfur-sulfur bond and is fairly stable when formed, but it is formed in only 1-2% yield in the above reaction. A more useful synthesis of this monomer is the reaction of thiocarbonyl fluoride with hexafluoropropylene epoxide at 175 °C. At this temperature hexafluoropropylene epoxide serves as a source of di-fluoromethylene, which adds to the double bond of thiocarbonyl fluoride to give the thiirane. If close control of conditions is maintained, yields are close to 40% (6). 

Mahler, W. Resnick, PR. Reversible difluorocarbene elimination from hexafluoropropylene epoxide. J. Fluorine Chetn. 1973, 3, 451. 

Storage Store refrigerated keep tightly closed store away from heat and direct sunlight store and use with adequate ventilation Uses Monomer for hexafluoropropylene epoxide polymers... 

PEG-10 bisphenol A dimethacrylate monomer, hexafluoropropylene epoxide polymers... 

These membranes are produced by Du Pont de Nemours (USA) under the registered trademark Nafion. To synthesize Nafion , tetrafluoroethylene is reacted with SO3 to form a cyclic sulphone. After rearrangement, the sulphone can then be reacted with hexafluoropropylene epoxide to produce sulphonylfluoride adducts, with m > 1... 

TEFLON" FEP was commercialized in 1959. At that time there appeared to be no hope of synthesis of a thermoplastic perfluorinated polymer of any structure other than FEP. Within two years the situation had changed as the result of a series of unexpected discoveries. For several years, research on the synthesis of perfluorocarbon epoxides had been underway in Du Pont, culminating in the discovery of a route to hexafluoropropylene epoxide (HFP0 )[5]. By 1960 sufficient HFPO had been made to permit exploration of its polymerization. This work shortly turned up an unusual polymerization system consisting of CsF initiator and polyethylene glycol ether solvent. Under the proper conditions this same system could be used to effect the condensation of HFPO with perfluorocarbon acid fluorides to produce perfluoroalkoxypropionyl fluorides [6]. These intermediates could be readily converted to perfluoroalkyl vinyl ethers by pyrolysis of their acid forms. 

The Objective of these, investigations was to prepare perfluorinated polyether elastomers having both good low temperature flexibility and high thennal stability. The ring opening polymerizations of hexafluoropropylene epoxide (HPPO) and octafluoro-isobutylene epoxide (OPIBO) were examined as a potential route to such materials. 

Perfluoroepoxid.es were first prepared ia the late 1950s by Du Pont Co. Subsequent work on these compounds has taken place throughout the world and is the subject of a number of reviews (1 5). The main use of these epoxides is as intermediates in the preparation of other fluorinated monomers. Although the polymerisation of the epoxides has been described (6—12), the resulting homopolymers and their derivatives are not significant commercial products. Almost all the work on perfluoroepoxides has been with three compounds tetrafluoroethylene oxide (TFEO), hexafluoropropylene oxide (HFPO), and perfluoroisobutylene oxide (PIBO). Most of this work has dealt with HFPO, the most versatile and by far the most valuable of this class of materials (4). 

Reaction of perfluoroaLkenes and hypochlorites has been shown to be a general synthesis of perfluoroepoxides (32) (eq. 7). This appears to be the method of choice for the preparation of epoxides from internal fluoroalkenes (38). Excellent yields of HFPO from hexafluoropropylene and sodium hypochlorite using phase-transfer conditions are claimed (34). 

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. 

A particularly important process for the synth sis of jluorinated monomers is attack of functionalized perfluoroalkoxides onto hexafluoropropylene oxide [271, 272, 273, 274] (equation 60) or other fluorinated epoxides [275, 276], resulting in ring-opening ol the epoxide and formation of a new perfluoroalkoxide or acid fluoride... 

Fluoride ion can also initiate ring opening of hexafluoropropylene oxide to give a heptafluoropropoxide, which can react in turn with the epoxide to give dimers or higher oligomers that are precursors to perfluorinated stable fluids [277, 27S, 279] (equation 61). 

HEXAFLUOROPROPENE see HDFOOO HEXAFLUOROPROPENE EPOXIDE see HDF050 HEXAFLUOROPROPENE OXIDE see HDF050 HEXAFLUOROPROPYLENE (DOT) see HDFOOO HEXAFLUOROPROPYLENE OXIDE (DOT) see HDF050... 

Oxiranes can be prepared by electrochemical oxidation. " Regioselective w-epoxidation of polyisoprenoids will take place with excellent yields on sodium bromide-promoted electrochemical oxidation in neutral or basic medium. " " This has now been described as a general method. " " Hexafluoropropylene oxiranes have been produced by electrochemical means. " The deoxygenation of dioxetane to oxirane with triphenylphosphine has been described (Eq, 50). ... 

Though it requires vigorous conditions and is less common than nucleophilic epoxidation, electrophilic epoxidation of aperfluoroalkene is possible with the potent combination of chromic oxide and fluorosulfonic acid, providing another route to hexafluoropropylene oxide (1). As a further example of electrophilic attack, hexa-fluoro Dewar benzene (3) is transformed into either a mono- or a diepoxide by the powerful hypofluorous acid-acetonitrile complex.The fact that the much weaker electrophile MCPBA readily epoxides such electron-deficient alkenes as ethyl pentafiuoromethacrylate (4) suggests that it actually reacts via nucleophilic attack at the [3-carbon. 

Trade Name Synonyms Cyracure UVR-6216 t[Dow http //www.dow.com] 1,2-Epoxy-1,1,2,3,3,3-hexafluoropropane CAS 428-59-1 EINECS/ELINCS 207-050-4 Synonyms Acetone, hexafluoro Hexafluoroepoxypropane Hexafluoro-1,2-epoxypropane Hexafluoropropene epoxide Hexafluoropropene oxide Hexafluoropropylene oxide Oxirane, trifluoro (trifluoromethyl)- Perfluoro (methyloxirane) Perfluoropropylene oxide Propane, 1,2-epoxy-1,1,2,3,3,3-hexafluoro-Propylene oxide hexafluoride ... 

Hexafluoropropene. See Hexafluoropropylene Hexafluoropropene epoxide Hexafluoropropene oxide. See 1,2-Epoxy-1,1,2,3,3,3-hexafluoropropane... 

It does not homopolymerize easily and hence can be stored as a liquid. It undergoes many addition reactions typical of an olefin. Reactions inclnde preparation of linear dimers and trimers and cyclic dimers (21,22) decomposition at 600°C with subsequent formation of octafluoro-2-butene and octafluoroisobutylene (23) oxidation with formation of an epoxide (24), an intermediate for a number of perflu-oroalkyl perfluorovinyl ethers (25,26) and homopolymerization to low molecular weight liquids (27,28) and high molecular weight solids (29,30). Hexafluoropropylene reacts with hydrogen (31), alcohols (32), ammonia (33), and the halogens and their acids, except I2 and HI (31,34-36). It is used as a comonomer to produce elastomers and other copolymers (37-41). The toxicological properties are discussed in Reference 42. 

Preparations of these 1,2-bis-electrophiles share some common features. In particular, esters of trifluoropyruvic acid (like MeTFP 1015) are available commercially, but they can be prepared in two steps from an epoxide 1067 (namely, hexafluoropropylene oxide, which is available on industrial scale) [633] (Scheme 228). hi turn, epoxides 1067 are obtained by oxidation of the corresponding perfluorinated alkenes, e.g. with hypochlorite [634]. 

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