Thermal degradation kinetics and lifetime estimation for polycarbonate/polymethylphenylsilsesquioxane composite

摘要

The thermal degradation behaviors of PC/polymethylphenylsilsesquioxane (PMPSQ) (FRPC) composites were investigated by thermogravimetric analysis (TGA) under isothermal conditions in nitrogen atmosphere and the isothermal kinetics equation was used to describe the thermal degradation process. The results showed that activation energy ( E ) in case of isothermal degradation was a quick increasing function of conversion (α) for PC and strong and decreasing function of conversion for FRPC. During the isothermal condition, the addition of PMPSQ retardanted the thermal degradation and enhanced the thermal stability of PC in the early and middle stages of thermal degradation in the presence of PMPSQ. It also indicated possible existence of difference in nucleation, nuclei growth and gas diffusion mechanism in thermal degradation process between PC and FRPC. Meanwhile, the addition of PMPSQ influenced the lifetime of PC, but the composite still meet the demand in manufacture and application.