热氧老化对红磷阻燃LGFPP复合材料性能的影响

摘要

用熔融共混法制备了长玻纤增强聚丙烯/红磷(LGFPP/RP)复合材料，并采用热烘箱老化法，研究了140℃条件下不同热氧老化时间对复合材料热氧老化性能的影响。结果表明，随着老化时间的延长，复合材料的结晶度减小，力学性能显著下降。说明分子量降低，发生了显著的热氧化降解。扫描电子显微镜显示，LGFPP/RP复合材料表面出现了明显的网状裂纹，局部范围还出现了较大的裂纹。PP基体分子链的断裂以及长玻纤与PP基体间发生界面脱粘是导致LGFPP/RP复合材料宏观力学性能下降的主要原因。红外光谱表明，随着热氧老化时间的延长，试样表面会产生更多的生色基团使材料发生黄变，说明PP基体分子链发生了老化断裂。%The composites based on long glass fiber reinforced polypropylene (LGFPP) and red phosphorus(RP) were prepared by melt blending. The thermal-oxidative aging properties of the composite with different thermal exposure time at 140℃were stu-died by means of oven heating. The results show that the crystallinity decreases and the mechanical properties decrease significantly as the aging time lasted,which indicate the molecular weight of PP matrix decreases and significant thermal-oxidative degradation happens. It is seen by SEM obvious reticular crack appears on the surface of LGFPP/RP composite and larger cracks appeared in local scope. The results indicate that the fracture of the molecular chain of PP matrix and debonding of the interface between LGF and PP matrix are the main reason for the decline in the mechanical properties. The results of FTIR show that the sample surface produces more chromophore leading to material yellowing,which confirms the fracture of the molecular chain of PP matrix as the aging time lasted.