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

Effects of Surface Modification on Micro-structure and Performance of Wood-fiber/PP Composites Enhanced by Nano-SiO_2

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%。

In order to study the dispersion state of surface treatment of nano-SiO2 in composites and its effects on the composites properties,the nano-SiO2 was modified by silane coupling agent KH570.The modifying effects of nano-SiO2 were characterized though CA,FTIR and contact angle meter.The dispersion state of modified nano-SiO2 in wood-fiber/PP were characterized by XRD and SEM,then the mechanical properties,snaking swell rate and water-absorption 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 nano-SiO2 is 62nm,and KH570 can successfully graft on the surface of nano-SiO2.The surface modification of nano-SiO2 improves the mechanical properties of wood fiber/PP being the most excellent,also reduces the snaking swell rate and water-absorption rate of the composites being the minimum.The tensile strength is 52.6MPa,the bending strength is 30 MPa,the impact strength is 11.8kJ/m2,increase by 75%,20% and 47.5%,respectively,comparing to that unmodified adding nano-SiO2.