微纳米SiO2/PP复合材料增强增韧的实验研究

为了研究无机刚性颗粒对通用塑料聚丙烯 (PP) 的力学性能的影响, 采用熔融共混方法制备了经硅烷偶联剂A-151处理的SiO₂/PP 复合材料, 并通过其缺口冲击、 拉伸、 弯曲试验和冲击断面的形貌观察, 分析研究了微纳米SiO₂颗粒大小、 填充量、 表面改性以及不同颗粒大小SiO₂混合物对PP复合材料增韧、 增强效果的影响。实验结果表明: 纳米SiO₂的加入可以同时改善其韧性、 刚性和强度; 填充量相同, 颗粒越细, SiO₂/PP复合材料的力学性能越好。SiO₂经改性后填充到PP基体中, 明显改善了颗粒在基体中的分散性及基体与颗粒之间界面结合性能, 使复合材料的综合力学性能得到提高。不同颗粒大小的SiO₂混合后填充到PP基体中, 混合SiO₂的协同效应使复合材料拉伸、 弯曲性能进一步提高, 对PP基体具有更好的增强效果, 但其冲击性能下降。

Toughening and strengthening of micro-and nano-SiO2/PP composites

In order to investigate the mechanical properties of commercial plastic polypropylene (PP) reinforced with inorganic rigid particles, the PP composite material filled with the surface-modified silica particles by silane coupling agent A-151 was prepared by the melt blending method. The effects of the particle size, mass fraction of silica, surface modification of silica and mixture of the silica particles with different sizes on the toughening and strengthening of PP matrix were investigated based on the results of mechanical properties testing and the observation of the impact fracture surface morphology of the composites. The results show that the toughness, strength and rigidity of the composites can be improved simultaneously by filling nano silica particles into polypropylene. The finer the size of the particles is, the higher the mechanical properties of the composites are. When the modified silica particles are filled into PP, the dispersion of the silica in PP matrix and the compatibility between the silica and matrix are improved, and the mechanical properties of the composites are improved. The composites reinforced with the mixture of the silica particles with different sizes have higher tensile and flexural properties. The mixture has a better reinforcing effect on PP matrix, but the impact property of the composites decreases.