Abstract: A modified resin system of N, N'-4, 4' -diphenylmethanebismaleimide (BMI)/o, o'-diallylbisphenol (DBA)/polycarbonate (PC) was prepared by melting prepolymerization. The mechanical properties, thermal stability, and structure of the resin were investigated．Both toughness and strength of the resin was obviously depecdent on the content of PC. When the loading of PC was 8 wt %, the tensile and impact strengths increased by 36.3 and strength 109.1 %, respectively．In addition, the modified resin system shjowed an excellent thermal stability. The PC phases with microsphere shape were uniformly dispersed in the BMI/DBA matrix.

Key words: N, N'-4, 4' -diphenylmethanebismaleimide, o, o'-diallylbisphenol, polycarbonate, toughening