耐高温杂化有机硅树脂的合成及复合材料的高温力学性能

摘要

Hybrid SiO2/Silicon resin was synthesized via a sol-gel route by using CH3Si(OCH3)3 and Si(OC2H5 )4 as primary materials and CH3OH as the solvent. The prepared hybrid SiO2/Silicon resin was characterized by Fourier transform infrared spectra ( FT-IR). The thermal properties and thermal degradation mechanism were investigated by thermo-gravimetric analysis (TG). Quartz fiber reinforced methyl silicon resin and TEOS-modified methyl silicon resin composites were prepared. The results show that flexural strength of TEOS-modified methyl silicon resin/quartz fiber can be improved with the addition of TEOS, especially the flexural strength of composites under high temperature. The morphologies of flexural fracture of composite with different ratio of TEOS were observed by scanning electron microscopy (SEM) ,and SEM microscopic studies show that the presence of TEOS in methylsilicone resin,to a large extent,improves interfacial strength between methyl silicon resin and quartz fiber under high temperature.%以一甲基三甲氧基硅烷(MTMS)和正硅酸乙酯(TEOS)为原料,甲醇为溶剂,通过溶胶—凝胶法制备出SiO2杂化有机硅树脂.借助傅立叶变换红外光谱(FT-IR)表征其高温结构变化,热失重分析(TG)研究SiO2杂化有基硅树脂的热稳定性和热降解机理.对TEOS改性甲基硅树脂/石英纤维复合材料在高温下的弯曲强度测试表明,TEOS的引入提高了甲基硅树脂复合材料的弯曲强度,尤其是高温条件下弯曲强度提高更加明显.通过扫描电子显微镜(SEM)对复合材料弯曲断口形貌观察表明,高温条件下,在甲基硅树脂中引入TEOS,能有效改善甲基硅树脂与石英纤维结合状况.