GB1355679A - Production of mouldable and or thermoformable polymers - Google Patents

Abstract

1355679 Polymers cross-linked with diepoxides ROHM & HAAS CO 9 July 1971 [20 July 1970] 32297/71 Heading C3B and C3P Mouldable and/or thermoformable viscous to solid polymers are formed by reacting at 20- 80‹ C. a mixture comprising (a) a monomer mixture comprising (i) 40-95 wt. per cent of one or more of styrene, substituted styrenes, and alkyl or cycloalkyl methacrylates, and (ii) 5-60 wt. per cent of at least one α,#- monoethylenically unsaturated carboxylic acid, and optionally, (iii) up to 5 wt. per cent of one or more other monomers; (b) at least one diepoxide of formula in which R 1 is H, halogen or C 1 -C 4 alkyl, and the other R's are hydrogen or C 1 -C 4 alkyl, the amount of diepoxide being such as to provide 0À1-2À0 epoxy groups per carboxylic acid group in (a) (ii); (c) a free radical initiator; and (d) a catalyst for acid-epoxide condensation, e.g. NaOH. In examples, polymerization is effected in bulk in the presence of tert.butylperoxy pivalate, one of two u/v absorbers, n-dodecyl mercaptan or mercaptoethanol as chain transfer agent, and a small amount of NaOH. The monomeres used are as follows:- (i) methyl methacrylate and mixtures thereof with styrene, vinyl toluene or butyl methacrylate, and mixtures of styrene with methyl-, ethylthioethyl-, ethyl- or cyclohexylmethacrylate; (ii) acrylic caid, methacrylic acid, itaconic acid or acrylic acid/methacryloxypropionic acid mixture; and (iii) acrylonitrile, vinyl acetate or methyl acrylate. The products may be moulded, e.g. into sheets or dome-shapes, and cured to give hard, solvent resistance products.