二氧化硅/ 聚酰亚胺纳米杂化薄膜室温及低温力学性能

利用溶胶-凝胶技术制备了不同SiO₂ 含量的二氧化硅/ 聚酰亚胺(SiO₂ / PI) 纳米杂化薄膜。采用红外光谱( IR) 和扫描电镜(SEM) 手段对该体系的分子结构和断裂形貌进行了表征, 研究了聚酰亚胺薄膜室温和低温(77K) 力学性能。结果表明: 室温和低温(77 K) 下, SiO₂ / PI 杂化薄膜的拉伸强度开始时均随SiO₂ 含量的增加而增加, 在含量为3 %时达到最大值, 低温下杂化薄膜的拉伸强度明显高于室温。室温下, 杂化薄膜的断裂伸长率在含量为3 %时达到最大值, 而低温(77 K) 下, 薄膜的断裂伸长率的变化没有呈现明显的规律性。 

MECHANICAL PROPERTIES OF POLYIMIDE COMPOSITES FILLED WITHSiO2 NANO-PARTICLES AT ROOM AND CRYOGENIC TEMPERATURES

In-situ sol-gel method was employed to prepare SiO2 / PI hybrid films with different silica content s. Themechanical properties at room temperature and cryogenic temperature (77 K) as a function of silica content werestudied. The result s show that the tensile st rength increases with the increasing of silica particles up to 3 % andthen decreases with the increasing of silica content at room and cryogenic temperatures. The cryogenic st rength isobviously higher than that at room temperature. The elongation at break reaches the maximum at 3 % silica contentat room temperature but has no obvious tendency at cryogenic temperature (77 K) . The molecular st ructure andmorphology of the fracture surfaces of hybrid films were analysed by using IR and SEM.