Verfahren zum Verringern der Loeslichkeit eines thermoplastischen Polymers

摘要

Thermoplastic polymers containing an unsaturated carboxylic acid ester of a substituted alkylene dioxolane, i.e. a plurality of groups where R1 is H or R11 and R11 is CH3 or C2H5, are cross-linked by subjecting the polymer to U.V. light of radiant energy 500-5000 Angstroms. The polymer may be the polymerization product of a mixture including where RIII is H, a C1-8 saturated aliphatic hydrocarbon or RIV and RIV is where n is 1-4 and R11 is as above; or may include where RIII and RIV are as above; or may include where Y is H, CH3, Cl2 or CN and n and R11 are as above; or the polymer may contain where the symbols are as above. The polymer may be a copolymer of the above esters and a monomer containing CH2=C=, e.g. styrene. A portion of the polymer may be masked and protected from exposure to the radiant energy. In examples, the polymers irradiated were a copolymer of styrene and the itaconyl ester of glyceryl ketal which was polymerized in acetone using benzoyl peroxide as catalyst; the styrene of the foregoing copolymer was replaced by vinyl acetate, methyl acrylate or methyl methacrylate; a copolymer of styrene and which was polymerized in toluene using 2,21-azobis-isobutyronitrile as catalyst; a copolymer of vinyl acetate and the foregoing ester which was polymerized in water containing polyvinyl alcohol and potassium sulphate; and copolymers of styrene, vinyl acetate, methyl acrylate or methyl methacrylate and ALSO:A copolymer of styrene and in toluene is used to coat wood and the polymeric film is then rendered insoluble by irradiation with U.V. light of 500-5000 Angstroms energy.