钛酸酯改性聚磷酸铵阻燃PP/PUR-T复合材料的性能

采用钛酸酯对聚磷酸铵(APP)进行表面改性,得到改性APP(TAPP),协同热塑性聚氨酯(PUR-T)阻燃聚丙烯(PP),通过测试冲击强度、热变形温度、极限氧指数(LOI)筛选综合性能最佳的TAPP与PUR-T配比,通过X射线衍射、扫描电子显微镜分析APP,TAPP和PUR-T对PP基复合材料结构的影响,同时研究了APP,TAPP和PUR-T对PP基复合材料的力学、流动、耐热和阻燃性能的影响。结果表明,TAPP或PUR-T的含量过多将造成冲击强度或耐热及阻燃性能的降低,TAPP∶PUR-T的质量比为1∶1时的综合性能最突出。PUR-T的添加改善了复合材料的冲击强度和流动性,降低了强度、热变形和维卡软化温度。APP的加入导致PP基复合材料的熔体流动速率和力学性能大大降低,而钛酸酯的表面改性则能显著改善流动性、力学性能和耐热性能。TAPP和PUR-T的协同加入显著改善了复合材料的力学和阻燃性能,冲击强度较纯PP和PP/APP复合材料分别提高了6%和56%,热变形温度较纯PP提高了11.3℃,以及LOI从纯PP的19.2%提高到了32.1%,UL-94阻燃等级达到V-1级。

Properties of Flame Retardant PP/PUR-T Composites Modified by Titanate-Ammonium Polyphosphate

Titanate was used to modify the surface of the ammonium polyphosphate(APP)to obtain modified APP(TAPP),subsequently,TAPP and thermoplastic polyurethane(PUR-T)used as a synergistic flame-retardant to polypropylene(PP).The ratio of TAPP/PUR-T with the best comprehensive performance was screened by testing impact strength,thermal deformation temperature and limiting oxygen index(LOI).The influences of APP,TAPP and PUR-T on the structure of PP matrix composites were analyzed by X-ray diffraction and scanning electron microscope.The effects of APP,TAPP and PUR-T on mechanical,flow,heat resistance and flame retardancy of PP matrix composites were studied.The results show that the excessive content of TAPP or PUR-T can reduce the impact strength or heat resistance and flame retardancy,the comprehensive performance is the most outstanding when the mass ratio of TAPP/PUR-T is 1/1.The addition of PUR-T improves the impact strength and fluidity of the composite,and reduces the strength,thermal deformation and Vicat softening temperature.The addition of APP leads to a great decrease in melt flow rate and mechanical properties of PP matrix composites,while the surface modification of titanate can significantly improve fluidity,mechanical properties and heat resistance.The synergic addition of TAPP and PUR-T significantly improves the mechanical and flame retardant properties of the composites,the impact strength increases by 6% and 56% respectively compared with pure PP and PP/APP composite,the thermal deformation temperature increases by 11.3℃compared with pure PP,the LOI value increases from 19.2% of pure PP to 32.1%,and the level test of UL–94 reaches V–1 level.