勃姆石/MPP二元协效AlPi阻燃PA66/GF复合材料研究

Study on AlPi Flame Retarded PA66/GF Composites with Binary Synergist of Boehmite and MPP

采用勃姆石部分替代传统的三聚氰胺聚膦酸盐(MPP)构成二元协效剂,与二乙基次膦酸铝(AlPi)复配协效阻燃尼龙66(PA66)/玻璃纤维(GF)复合材料。勃姆石的引入对复合材料的力学性能影响较小,但是能显著提高流动性,提高材料的可加工性。采用勃姆石1∶1替代MPP后,复合材料的阻燃性能并没有显著提升,但是部分替代MPP后,锥形量热和垂直燃烧测试结果均显示,复合材料的阻燃性能提升明显,热释放速率峰值(pHRR)由279.4kW/m^2降低至158.6kW/m^2,垂直燃烧阻燃等级由V–1级提高至V–0级。扫描电子显微镜(SEM)结果表明,勃姆石和MPP构成二元协效体系,能够提高材料的成炭性能以及炭层的致密度。在相同的阻燃效率条件下,勃姆石和MPP二元协效能够降低MPP和AlPi的用量,体现出良好的经济性。同时,勃姆石的部分引入能够减少材料在湿热老化过程中阻燃剂的析出数量。

Combining with melamine polyphosphate (MPP),the boehmite was used to partly replace MPP as synergists of aluminum diethylphosphinate (AlPi) to improve the flame retardancy of nylon 66 (PA66)/glass fiber (GF) composites. The addition of boehmite has less influence on the mechanical properties of PA66/GF composites,but can enhance the fluidity of the material, resulting in better molding performance. The flame retardancy of composite keep changeless while replaced the MPP with boehmite at the mass ratio of 1∶1,however,when partly replaced MPP with boehmite,the results of cone calorimeter and vertical combustion show that binary synergists of boehmite and MPP can enhance the solid phase flame retardancy of composites,the peak heat release rate is reduced by 158.6 kW/m^2 from 279.4 kW/m^2,the flame retardant rating is improved to V–0 from V–1. The scanning electron micro (SEM) results show that binary synergist of boehmite and MPP can improve charring process and compactness of char layer. Binary synergist of boehmite and MPP can reduce the dosage of MPP and AlPi while keep the flame retardancy constant, which shows great efficiency. Besides,the addition of boehmite can reduce the precipitation of flame retardants in composites after hydrothermal aging.