GB739731A - Improvements in or relating to new vinyl fluorinated alkyl ethers and their polymers - Google Patents

Abstract

Polymers are produced by polymerization of vinyl 1,1-dihydroperfluoroalkyl ethers having from 6 to 14 carbon atoms in the molecule, represented by the formula CnF2n + 1CH2OCH = CH2 (see Group IV (b)). Copolymers may be obtained by polymerizing a mixture of two or more of the vinyl 1,1-dihydroperfluoroalkyl ether monomers or a mixture of the novel ether monomers and polymerizable monomers of other kinds which contain an ethylenic linkage, e.g. acrylonitrile, vinyl acetate, styrene, methyl acrylate, methyl methacrylate, isoprene and butadiene which may be halogenated. Catalysts mentioned include peroxides such as acetyl and benzoyl peroxides and cumene hydroperoxide, boron trifluoride and ultra-violet light. The properties of the polymer masses may be varied by the use of plasticizers and by the addition, e.g. of carbon black or zinc oxide. A polyfunctional compound may be added at the time of polymerization to cause cross-linking between chains to form a three-dimensional network. In examples vinyl 1,1-dihydroperfluorobutyl ether is polymerized using a boron trifluoride/ethyl ether complex and benzoyl peroxide as catalysts, the latter with and without ultra-violet light and ultra-violet light only to obtain polymers varying from viscous oils to rubbery solids (1) and viscid liquids are obtained by polymerization of vinyl 1,1-dihydroperfluorohexyl ether in the presence of the boron trifluoride diethyl ether complex. Specifications 686,678, [Group IV (b)], and 703,434 are referred to.ALSO:The invention comprises vinyl 1,1-dihydroperfluoroalkyl ethers having from 6 to 14 carbon atoms in the molecule represented by the formula CnF2n + 1CH2-O-CH = CH2. Polymers are produced by polymerization of the said vinyl 1,1-dihydroperfluoroalkyl ethers (see Group IV (a)). Acetoxy derivatives may be formed by the addition of acetic acid of the formula CnF2n + 1CH2O-CH(CH3)-OOCCH3 and by addition of trifluoroacetic acid the corresponding derivative may be formed. Acetal derivatives may be formed by the addition of alcohols including 1,1 - dihydroperfluoroalkyl alcohols CnF2n + 1CH2OH by reacting with vinyl acetate in the presence of a mercuric catalyst such as mercuric sulphate and a polymerization inhibitor such as hydroquinone. In examples vinyl 1,1 - dihydroperfluorobutyl ether is prepared by reacting 1,1-dihydroperfluorobutyl alcohol with vinyl acetate in the presence of hydroquinone, sulphuric acid and mercuric acetate, the reaction is stopped by adding sodium acetate to reduce acetoxy acetal formation and the desired product is obtained from the reaction product by washing and fractionation. A vinyl 1,1-dihydroperfluoroalkyl etheracetic acid addition product, CF3(CF2)2CH2OCH (CH3)OOCCH3 is obtained as by-product (1); and vinyl 1,1-dihydroperfluorohexyl ether is obtained by reacting 1,1-dihydroperfluorohexyl alcohol and vinyl acetate in the presence of hydroquinone and a mercuric sulphate catalyst formed in situ and washing, extracting and fractionating the product (2). The products are shown to be polymerizable. Dihydroperfluoroalkyl alcohols may be prepared by reduction with lithium aluminium hydride of fluorocarbon monocarboxylic acids of the formula CnF2n + 1COOH, by reduction of the corresponding acid chlorides or by hydrogenation of methyl esters of fluorocarbon acids of the formula CnF2n + 1COOCH3 using a copper chromium oxide catalyst containing a trace of barium at elevated temperature and pressure. Specifications 686,678 and 703,434 are referred to.