Abstract: The effect of poly(methyl phenylsilsesquioxane)(PMPSQ)on flame retardantrheological, thermal and mechanical properties of polycarbonate(PC) was investigated. As the content of PMPSQ increased from 0 to 5 %the impact strength of PC increased by 71.5 %and the LOI value increased by23%.Further increasing the content ofPMPSQ,no additional improvement was observed.The in-clusion of PMPSQ reduced the glasstransition temperature(T)of PCPMPSQof 5%caused T.of PC decreased from 144.5℃ to 139.1℃.PMPSQ also resulted in reduction of the apparent viscosity of PC and thus enhanced its processability.

Key words: poly(methyl phenylsilsesquioxane);polycarbonate;flame retardancy;processability, mechanical property