Aimed at raising the heat resistance of poly ( vinyl chloride ) ( PVC ), N - phenyl maleimide ( PMI ) / styrene ( St ) / acrylonitrile ( AN ) terpolymer as modifier of heat resistance was synthesized with suspension polymerization process in this paper. 以提高聚氯乙烯(PVC)的耐热性能为目的,用悬浮聚合的方法,合成了N-苯基马来酰亚胺-苯乙烯-丙烯腈三元共聚物型耐热改性剂。