Thermal and Thermo-oxidative Degradation of Flame Retardant High Impact Polystyrene with Triphenyl Phosphate and Novolac Epoxy Resin

Thermal and thermo-oxidative decomposition and decomposition kinetics of flame retardant high impact polystyrene (HIPS) with triphenyl phosphate (TPP) and novolac type epoxy resin (NE) were characterized using thermo-gravimetric experiment. And the flammability was determined by limited oxygen indices (LOI). The LOI results show that TPP and NE had a good synthetic effect on the flame retardancy of HIPS. Compared with pure HIPS,the LOI values of HIPS/NE and HIPS/TPP only increased by about 5%,and the LOI value of HIPS/TPP/NE reached 42.3%,nearly 23% above that of HIPS. All materials showed one main decomposition step,as radical HIPS scission predominated during anaerobic decomposition. TPP increased the activity energy effectively while NE affected the thermal-oxidative degradation more with the help of the char formation. With both TPP and NE,the materials could have a comparable good result of both thermal and thermal-oxidative degradation,which could contribute to their effect on the flame retardancy.