GB640468A - Improvements in copolymers of dipropenyl esters - Google Patents

Abstract

Soluble unsaturated resins capable of ultimate conversion to a solvent and heat resistant state are prepared by copolymerizing a mixture of a dipropenyl ester of an alpha-beta unsaturated dicarboxylic acid and an omega trichloralkene. The preferred esters are those of acids having the general formula Cn H2n-2(COOH)2, where n is from 2 to 6 and include allyl, 2-alkyl- and 2-chloro-allyl esters of maleic, fumaric, itaconic, citraconic and mesaconic acids. Esters of ethyl-fumaric, ethyl-maleic, propyl-fumaric and a -hydromuconic acids are also mentioned. The preferred omega-trichlor-alkenes are those also containing a terminal ethylene linkage, e.g. 3,3,3-trichloropropene-1, 4,4,4-trichlorobutene-1 and 4,4,4 - trichloro - 2 - methylbutene - 1. Polymerization is effected at 25-120 DEG C. in the presence of a peroxidic catalyst such as benzoyl peroxide, acetyl benzoyl peroxide, tert.-butyl hydroperoxide, succinyl peroxide and tert.-butyl perbenzoate. The products which are soluble in acetone, benzene, chloroform, carbon tetrachloride, ethyl acetate and xylene may be purified by repeated solution in a solvent and precipitation with a non-solvent, e.g. n-hexane, or may be dissolved without isolation. Dyes, pigments, fillers, plasticizers and resins may be incorporated before curing the copolymers by the application of heat. The copolymers may be interpolymerized with ethylenic compounds, e.g. butyl methacrylate, allyl acrylate, vinyl acetate and styrene, by dissolving them in these monomers and heating in the presence of a catalyst to the infusible state. An example is also given of dissolving the copolymer in diethyl fumarate and curing in a mould. The copolymers which are non-dissolving and fire-retardant, may be cast and moulded into rods, blocks and sheets or used for impregnating or coating furnishings.