GB785159A - Method of preparation of mouldable copolymers of styrene and acrylonitrile - Google Patents

Abstract

Thermoplastic copolymers are prepared by heating at a temperature between 130 DEG and 175 DEG C. a homogeneous liquid mixture comprising a polymerizable composition consisting of 20 to 35 per cent of acrylonitrile, 80 to 35 per cent styrene and 0 to 30 per cent alpha-methyl styrene and a polymerization modifier amounting to 10 to 40 per cent of the reaction mixture consisting of benzene, an alkyl benzene, or a nuclear derivative thereof, continuing heating until the reaction mixture contains not more than 70 per cent of copolymer and separating from the resulting mixture a copolymer having a viscosity of from 6 to 40 c.p. when measured as a 10 per cent solution in butanone at 25 DEG C. Substituted benzenes specified are toluene, xylenes, polymethylbenzenes, ethylbenzene, ethyltoluenes, ethylxylenes, diethylbenzenes, diethyltoluenes, polyethylbenzenes, isopropylbenzene, isopropyltoluenes, isopropylxylenes, isopropylethylbenzenes, isopropyldiethylbenzenes, diisopropylbenzenes, diisopropyltoluenes, polyisopropylbenzenes, chlorobenzene, di-, tri-, and polychlorobenzenes, nuclear mono-, di-, tri-and poly-chlorotoluenes, and nuclear mono- and polychlorinated ethylbenzenes. Polymerization may be carried out in a batch, semicontinuous or continuous manner and is preferably conducted in the absence of a catalyst, although an organic peroxygen compound may be present if desired.