GB871440A - Improvements in epoxidation - Google Patents

Abstract

Esters of epoxy alcohols and a , b -olefinic acids (such as acrylic, crotonic, and higher homologues) obtained by reacting with an epoxidizing agent an ester of the formula R1CH=C(R2). COO(CH2)xC(R3)= =C(R4)(R5) wherein R1 to R5 represent hydrogen or saturated or aromatic hydrocarbon radicals and at least one of R1 and R2 is hydrogen, x is an integer from 1 to 5, so as to epoxidize the alcohol residue only, are useful as plasticizers and stabilizers for vinyl halide resins. They may also be polymerized through either the olefinic group or the epoxy group or both. Thus an epoxyalcohol 2-alkenoate can be polymerized with vinyl chloride to give a copolymer which can then be cross-linked through the epoxy group by treatment with an acid or base. Alternatively such an ester can be copolymerized with ethylene oxide to form a copolymer capable of cross-linking through the double bonds by treatment with a peroxide or by heating at an elevated temperature.ALSO:An ester of an epoxy alcohol and an alkenoic acid is produced by reacting together an epoxidising agent and an ester of the formula: <FORM:0871440/IV (b)/1> wherein R1, R2, R3, R4 and R5 each represent hydrogen or saturated hydrocarbon radicals, at least one of R1 and R2 is hydrogen, and X is an integer from 1 to 5, said reaction being conducted for a time sufficient to consume up to one mole of epoxidising agent per mole of said ester, thus introducing an oxirane oxygen into the alcohol residue of said ester. The epoxidising agent is preferably peracetic acid but acetaldehyde monoperacetate, perbenzoic acid or monoperphthalic acid may be used. The reaction temperature may vary between 0 DEG and 100 DEG C. It is preferred to use between 5 and 25 mole per cent excess of epoxidising agent. The reaction may be conducted in an inert medium such as acetone, diethyl ether or acetone. A vinyl polymerization inhibitor may be present. The product 2,3-epoxy-2-methyl-propyl crotonate is a novel compound. The ester starting materials may be synthesized by reacting an appropriate unsaturated alcohol with an appropriate a ,b -unsaturated acid, anhydride or acid halide, in the presence of a catalyst such as p-toluene sulphonic acid. The epoxy products may be used as plasticizers and stablizers for vinyl halide resins and may also be polymerized through both the epoxy group and the double bond to form polymers.