改性纳米SiO2/硅橡胶复合材料的制备及性能

为提高纳米SiO₂在硅橡胶（SR）基体中的分散性及两相间的界面结合力，设计以羟基硅油（HSO）和γ-甲基丙烯酰氧基丙基三甲氧基硅烷（KH570）为纳米SiO₂的表面封端改性剂，并将改性SiO₂与双组份加成型液体SR复合得到改性纳米SiO₂/SR复合材料。通过一系列表征手段对改性纳米SiO₂的形貌结构及其在乙醇中的分散性等进行分析，研究了改性纳米SiO₂对纳米SiO₂/SR复合材料的断面形貌、力学性能及热稳定性的影响。结果表明：KH570成功接枝到纳米SiO₂表面并与SR基体间形成化学键。当HSO协同KH570改性纳米SiO₂时，可有效改善纳米SiO₂在SR基体中的分散性能及纳米SiO₂与SR两相间的界面结合性能，并显著提高纳米SiO₂/SR复合材料的力学性能和热稳定性。将SiO₂∶HSO∶KH570以质量比为2.0∶0.2∶0.6处理的改性纳米SiO₂粒子，得到的改性纳米SiO₂/SR复合材料起始热分解温度提高了230℃。当SiO₂∶HSO∶KH570质量比为2.0∶0.2∶0.45时，改性纳米SiO₂/SR复合材料的拉伸强度和断裂伸长率分别提高了约1倍。

Preparation and properties of modified nano SiO2/silicone rubber composites

To improve the dispersibility of nano SiO₂ particles in silicon rubber (SR) and the interfacial bonding performance of the two phases, the surface modification agent consisting of hydroxyl silicone oil (HSO) and 3-(trimethoxysilyl)propylmethacrylate (KH570) for nano SiO₂was designed. And the modified nano SiO₂/SR composites were prepared. The morphology structure of nano SiO₂ and the dispersibility of nano SiO₂in the ethanol were investigated, the fracture surface morphology, mechanical properties and thermal stability of the modified nano SiO₂/SR composites were also analyzed. The results show that KH570 is successfully grafted to the surface of nano SiO₂ and formes chemical bonds with the SR matrix. When the nano SiO₂ is treated by the hybrid surface modification agent (HSO cooperated with KH570), the dispersibility of SiO₂ in SR matrix, and the interface bonding performances between SiO₂ and SR are improved obviously, the mechanical properties and thermal stability of the SiO₂/SR composites are also enhanced significantly. When SiO₂:HSO:KH570 mass ratio is 2.0:0.2:0.6, the initial temperature of thermal decomposition of the modified nano SiO₂/SR composite increases to 230℃. When SiO₂:HSO:KH570 mass ratio is 2.0:0.2:0.45, the tensile strength and elongation at break of the modified nano SiO₂/SR composite increase twice, respectively.