目的 研究聚丙烯复合材料的燃烧行为和纳米SiO2含量对复合材料力学性能的影响。方法 采用熔融共混方法， 将聚丙烯、 氮磷复配阻燃剂及表面改性的纳米SiO2制备成聚丙烯复合材料。结果在燃烧过程中纳米SiO2对阻燃性能有一定影响， 氮磷复配阻燃剂是影响复合材料阻燃性能的关键因素。随着纳米SiO2含量的增加， 复合材料的极限氧指数先增加后降低， 当纳米SiO2质量分数为1%时，复合材料的极限氧指数最大。随着纳米SiO2含量的增加， 复合材料的拉伸、 冲击、 弯曲强度和弯曲模量呈现先增大后减小的现象。结论 氮磷复配阻燃剂与纳米SiO2对于复合材料有一定的协同阻燃效果。当纳米SiO2质量分数为1%时， 复合材料的阻燃及力学性能最优。

This work aimed to study the burning behavior of polypropylene composites and the effect of nano-SiO2 content on the mechanical properties of the composite. By means of melt blending method, polypropylene, nitrogen and phosphorus compound flame retardant and surface modified nano-SiO2 composite materials were mixed to prepare polypropylene composites. The results showed that: in the process of combustion, nano-SiO2 had some effects on the flame retardancy, and the nitrogen and phosphorus compound flame retardant was a key factor affecting the flame retardancy of the composites. With increasing nano-SiO2 content, the limiting oxygen index of the composites first increased and then decreased. When the nano-SiO2 content was 1% , the limiting oxygen index of the composites was the maximum. With increasing Nano-SiO2 content, the tensile, impact and bending strength as well as the flexural modulus first increased and then decreased. There was a certain synergistic flame retarding effect of nitrogen and phosphorus compound flame retardant and nano-SiO2 on the composite materials. When the nano-SiO2 content was 1% , the composites with optimal flame retardancy and mechanical properties were obtained.