| 摘要 |
Copolymers with high impact strength comprise 64-94% of a substituted or unsubstituted styrene, 35-5% of an ester, amide or nitrile of acrylic or methacrylic acid and 1-25% of a mixture containing 35-80% polyisoprene and 65-20% polybutadiene, all percentages being by weight. The polymerization is preferably carried out by heating the above compounds in the presence of a catalyst, chain terminator and a suspending agent in an aqueous suspension at a temperature between 60 DEG and 150 DEG C. under autogenous pressure for up to twelve hours. The styrene is preferably an alkyl styrene such as a -methyl styrene or ethyl styrene or a halostyrene, and the acrylic compound is preferably acrylonitrile. The catalyst preferably is a radical producer such as benzoyl peroxide, the chain terminator an alkyl or aryl mercaptan or a low molecular weight polymer of a -methylstyrene. Compounds such as methyl cellulose, ethyl cellulose, polyvinyl alcohol or a potassium salt of a styrene-maleic anhydride copolymer are used as suspending agent. |
