PPO-Graft copolymer and process for producing the same

摘要

A graft copolymer having enhanced moldability with high mechanical strength capable of forming a molded article having excellent gloss, transparency and color is prepared by grafting styrene polymer segments formed under specific conditions selected onto the backbone polymer of polyphenylene ether. Said styrene polymer segments are formed by melting and kneading continuously a mixture of (a) polyphenylene ether expressed by the general formula of: <IMAGE> WHEREIN R1 and R2 represent an alkyl group having 1-4 carbon atoms or a halogen atom, respectively, and n represents the degree of polymerization and is 90-250, (b) a styrene polymer containing at least 80 weight % of styrene units and (c) styrene-containing monomers in the presence of a radical initiator at a temperature in the range from 160 DEG to 300 DEG C thereby to complete graft polymerization within a time ranging from 0.5 to 15 minutes, preferably under uniform mechanical shearing stress throughout said mixture during graft polymerization.