GB634673A - Fluorinated olefin polymers - Google Patents

Abstract

A polymer or copolymer of a fluorinated olefin containing more than two carbon atoms and in which the olefin is free from monofluorinated carbon atoms and has at least one polyfluorinated carbon atom is made by subjecting the olefin alone or with another polymerizable organic compound to polymerization conditions of temperature and pressure in the presence of a peroxy catalyst. The fluorinated olefin may be 3,3,3-trifluoropropene; 2-methyl-3,3,3 - trifluoropropene; 3,3 - difluoropropene; 1,1-difluoropropene; 1,1,3,3-tetrafluoropropene; 4,4,4 - trifluorobutene; 3,3 - difluorobutene; 3,3,4,4,4 - pentafluorobutene; 1,1 - difluoro - 1 - butene; 3,3,3 - trifluoro - 2 - trifluoromethylpropene; 3,3-difluoropentene; 4,4-difluoro - 1 - pentene; 1,1 - difluoro - 1 - pentene; 4,4,5,5,5 - pentafluoro - 1 - pentene or 5,5,5-trifluoro - 2 - pentene. One or more other halogen atoms may be present in the above fluorinated olefins. The peroxy catalyst may be acetyl, propionyl, benzoyl, acetyl benzoyl, succinyl or lauroyl, peroxide, tertiary butyl hydroperoxide, tertiary butyl peroxide, or the sodium, potassium and ammonium salts of perphosphoric or persulphuric acids. The polymerization may be effected in a solvent for the olefin and catalyst such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diamyl phthalate, ethyl phenylacetate, amyl acetate, heptane, 1-4-dioxan or dibutyl ether. The other polymerizable organic compound may be another fluorinated olefine or styrene, vinyl ethers, diolefins, acrylic acid, dimethyl maleate or maleic anhydride. The polymers or copolymers may be used as lubricants.ALSO:In the preparation of polymeric fluorinated olefins the preparation of two monomers is described. In example (1), 3,3,3-trifluoropropene is prepared by chlorinating propylene chloride in the dark using as catalyst iron filings, treating the so-formed trichloropropane with sodium hydroxide solution, and heating the resulting dichloropropene in a pressure vessel with anhydrous hydrogen fluoride at a maximum pressure of 800 lbs. per sq. inch, to effect conversion to trifluoropropane. The trifluoropropane is then converted to 3-chloro-1,1,1-trifluoropropane by photochemical chlorination of the trifluoropropane in the vapour state and the desired 3,3,3-trifluoropropene obtained from the 3-chloro-1,1,1-trifluoropropane by treating with alcoholic potash. In example (2), 2-methyl-3,3,3-trifluoropropene is prepared by treating amyl trifluoroacetate with methyl magnesium iodide to yield, after decomposition of the Grignard compound, 2-methyl-1,1,1-trifluoro-2-propanol, which after dehydration with phosphorus pentabromide yields the desired monomer.