表面改性对纳米SiO_2增强木纤维/PP复合材料微观结构及性能的影响

为研究经表面处理的纳米SiO_2在复合材料内的分散状态及其对复合材料性能的影响,选择硅烷偶联剂KH570对纳米SiO_2进行表面改性,分别通过激光粒度仪、傅里叶红外光谱分析仪、接触角测定仪表征纳米SiO_2的改性效果,采用XRD、SEM对经表面处理后的纳米SiO_2在木纤维/PP内的分散状态进行表征,测试并分析其力学性能、吸水膨胀率和吸水率。结果表明:当KH570的质量分数为5%时,纳米SiO_2的平均粒径为62nm,KH570可以成功接枝在纳米SiO_2表面。其对木纤维/PP复合材料的力学性能提高最优,吸水膨胀率与吸水率最低,弯曲强度达到52.6 MPa,拉伸强度为30MPa,冲击强度可以达到11.8kJ/m2;相比添加未经过表面改性的纳米SiO_2,分别提高了75%,20%和47.5%。

Effects of Surface Modification on Micro-structure and Performance of Wood-fiber/PP Composites Enhanced by Nano-SiO2

In order to study the dispersion state of surface treatment of nanoSiO2in composites and its effects on the composites properties, the nanoSiO2was modified by silane coupling agent KH570.The modifying effects of nanoSiO2 were characterized though CA, FTIR and contact angle meter. The dispersion state of modified nanoSiO2 in woodfiber/PP were characterized by XRD and SEM, then the mechanical properties, snaking swell rate and waterabsorption of the composites were test and analyzed. The results show that when the mass fraction of KH570 is 5%, the average particle size of the modified nanoSiO2 is 62 nm, and KH570 can successfully graft on the surface of nanoSiO2.The surface modification of nanoSiO2 improves the mechanical properties of wood fiber/PP being the most excellent, also reduces the snaking swell rate and waterabsorption rate of the composites being the minimum. The tensile strength is 52.6 MPa,the bending strength is 30 MPa, the impact strength is 11.8 kJ/m2, increase by 75%, 20% and 47.5%, respectively, comparing to that unmodified adding nanoSiO2.