Flame Retardant Properties and Mechanical Properties of Polypropylene with Halogen and Halogen-Free Flame Retardant System

In this study, to improve the flame retardancy properties of polypropylene, DBDPE/Sb₂O₃ and DBDPE/HBCD/Sb₂O₃ flame retardant systems were used for flame retardant PP, and a halogen-free flame retardant PP material was prepared using the one-component intumescent flame retardant PNP1D. Tensile tests, impact tests, ultimate oxygen index, UL94V-0 vertical combustion, thermogravimetric analysis, rheological analysis and scanning electron microscopy were used to study the flame retardant properties and mechanical properties of the flame retardant PP. The test results show that both the ultimate oxygen index of DBDPE/Sb₂O₃ compounded flame retardant PP and the ultimate oxygen index of PNP1D flame retardant PP are nearly double that of pure PP, passing the UL-94V-0 flame retardant standard. The thermal decomposition temperature range of DBDPE/Sb₂O₃ compounded system and the thermal decomposition temperature range of PNP1D flame retardant PP both completely cover the thermal decomposition temperature range of both the DBDPE/Sb₂O₃ compound system and PNP1D flame retardant PP completely covered the thermal decomposition temperature range of pure PP. The tensile and impact strength of the DBDPE/Sb₂O₃ flame retardant system with 10% SK-80 is 50% higher than that of the DBDPE/Sb₂O₃ flame retardant system without SK-80. The modified PP with 25% PNP1D is nearly 1 time higher than pure PP in terms of carbon formation and has an ideal flame retardant effect.