表面改性纳米SiO2增强木质纤维/聚氯乙烯复合材料性能

SiO₂粒子经偶联剂γ-氨丙基三乙氧基硅烷（KH550）表面改性后，与木质纤维、聚氯乙烯（PVC）及其它助剂通过熔融混炼制备改性SiO₂-木质纤维/PVC复合材料，用FTIR、SEM和同步热分析仪（STA）对SiO₂粒子和SiO₂-木质纤维/PVC复合材料的结构与性能进行测试与表征。FTIR分析表明，SiO₂粒子表面接枝了KH550的特征官能团，KH550成功地接枝到SiO₂粒子表面；SEM分析表明，改性纳米SiO₂粒子能在木质纤维/PVC复合材料中均匀分散，其粒径在100 nm左右；添加改性的SiO₂粒子后，木质纤维和PVC结合更加紧密，孔洞间隙减少。纳米SiO₂质量分别占木质纤维质量的10%、8%和10%时，SiO₂-木质纤维/PVC复合材料的弹性模量、拉伸强度、冲击强度分别达到最优值4.66 GPa、31.12 MPa和4.11 kJ/m²，与未添加SiO₂的复合材料相比分别提高了50.29%、28.91%和16.65%。

Properties of wood fiber/polyvinyl chloride composites reinforced by surface modified nano SiO2

The surface modification of nano SiO₂ particles with γ-aminopropyl triethoxysilane(KH550) was carried out, The SiO₂-wood fiber/polyvinyl chloride(PVC) composites were prepared by melt-mixing with wood fiber, PVC and other additives. The structure and properties of SiO₂ particles and SiO₂-wood fiber/PVC composites were tested and characterized by FTIR, SEM and STA.FTIR analysis shows that the surface of SiO₂ particles bond KH550 characteristic organic functional group, KH550 successfully grafts to the surface of SiO₂ particles. SEM analysis shows that the modified nano-SiO₂ particles can be dispersed uniformly in the SiO₂-wood fiber/PVC composites with a particle size of about 100 nm; After adding the modified SiO₂ particles, the combination of wood fiber and PVC is more tight, the hole gap is reduced. When the mass ratio of nano SiO₂ to wood flour mass is 10%, 8%, 10%, the mechanical property of the SiO₂-wood fiber/PVC composites will reach the optimal state:elastic modulus, tensile-strength and impact-strength are 4.66 GPa, 31.12 MPa and 4.11 kJ/m², increased by 50.29%, 28.91% and 16.65%, respectively.