无规聚苯基硅倍半氧烷阻燃聚碳酸酯的性能

采用笔者自制的无规聚苯基硅倍半氧烷(IPPS)与聚碳酸酯(PC)通过双螺杆挤出机熔融共混,制得不同含量IPPS的PC/IPPS复合物。利用极限氧指数(LOI),垂直燃烧等级(UL-94)和锥形量热仪对PC/IPPS复合物的燃烧性能进行了表征;通过拉伸强度、弯曲强度及弯曲模量对PC/IPPS复合物的力学性能进行了表征;通过热失重分析了IPPS对PC热性能的影响。实验表明,当添加质量分数8%的IPPS时,可以使PC的极限氧指数(LOI)从26%提高到35.5%,UL-94(1.6mm)燃烧级别从无级别提高到V-0;热释放速率峰值(PHRR)从570.8 kW/m2降到267.3 kW/m2。燃烧后的炭层表面被白色的二氧化硅覆盖,很好地阻隔辐射热和氧向基材的传递。IPPS使得PC的力学性能有轻微的下降,不改变PC的降解路径。

Flame Retardant Properties of Polycarbonate/ Irregular Polyphenylsilsesquioxane Composites

Irregular polyphenylsilsesquioxane(IPPS) was independently synthesized in our laboratory.IPPS mixed with polycarbonate(PC) by the twin-screw extruder to prepare PC/IPPS composites.The flammability of the PC/IPPS composites was characterized by limiting oxygen index(LOI),UL 94 burning rating and Cone calorimeter test.The mechanical properties of PC/IPPS composites,such as tensile strength,flexural strength and modulus,were tested.The thermal properties were analyzed through the thermal gravimetric analysis(TGA).The results show that the LOI value of PC/8% IPPS composite can achieve 35.5% comparing with 26% of pure PC,and UL94(1.6mm) can reach V-0 rating.The peak heat release rate(PHRR) decreases from 570.8 kW/m2 to 267.3 kW/m2 in the 8% IPPS loading.The surface of char residues is covered by white silica,which can prevent transfer of the heat and oxygen to PC matrix.The mechanical properties of PC with IPPS loading has a slightly decrease.However,the addition IPPS has no effect on the thermal degradation path of PC matrix.