【摘要】 采用溶胶-凝胶法,以一甲基三乙氧基硅烷(MTES)和正硅酸乙酯(TEOS)为原料,乙醇为溶剂,盐酸为催化剂,通过溶胶-凝胶法制备出分子级复合的SiO2杂化有机硅树脂,浸涂在聚酰亚胺表面干燥后获得了透明致密的涂层。采用自己研制的空间综合环境地面模拟设备对试样进行了原子氧暴露实验。测试表明,溶胶-凝胶制备的有机硅/SiO2涂层抗原子氧侵蚀性能优异,抗原子氧侵蚀性能比聚酰亚胺基体提高了2个数量级以上。经AO暴露后的杂化涂层质量几乎没有发生变化。经FTIR和XPS分析表明,在原子氧暴露后涂层表面产生的是SiO2陶瓷层。SEM分析表明无涂层的聚酰亚胺原子氧暴露后表面非常粗糙,表面呈现地毯状形貌而涂覆涂层试样暴露前后表面形貌没有发生变化。采用紫外-可见光-近红外分光光度计对涂覆有机硅/SiO2涂层试样分析表明,原子氧暴露前后试样表面的光学性能也未发生变化。实验证明,制备抗原子氧侵蚀的防护涂层的溶胶-凝胶法是一种行之有效的方法。更多还原

【Abstract】 SiO2/siloxane hybrid coatings on polyimide substrates were synthesized with CH3Si (OC2H5)3 and Si(OC2H5)4 as raw materials, hydrochloric acid as catalyst and C2H5OH as solvent by sol-gel method. The coatings irradiated by atomic oxygen generated in a ground simulation facility were investigated by Scanning Electron Microscopy (SEM), X-Ray Photoelectron Spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR). The results show that the siloxane/SiO2 coatings have excellent AO resistance. The siloxane/SiO2 hybrid coating have an erosion rate two orders of magnitude slower than the polyimide film, and do not crack during AO exposure. The results indicate that a passive inorganic SiO2 layer is formed on the silxoane/SiO2 hybrid coatings during AO exposure. This SiO2 layer could retard the inward penetration of oxygen atoms effectively, preventing further degradation of the bulk polymer. The coatings have no influence on the optical property of the substrate materials. The results demonstrate that the coatings prepared by sol-gel technique have potential applications in spacecraft materials.更多还原