【摘要】 采用不同陈化时间的酸催化硅溶胶制备SiO2含量一定的聚酰亚胺/二氧化硅杂化薄膜,用FTIR-ATR、SEM、TMA等手段对其微相结构、热稳定性、力学性能进行了研究。结果表明:随着硅溶胶水解和聚合反应的进行,杂化薄膜中的SiO2颗粒由棒状长大为球体,并逐渐团聚、变形,薄膜的光学透明性降低,热膨胀系数逐渐减小,拉伸强度先增大后减小。当球形SiO2颗粒的直径小于1μm且均匀分布在基体中时,薄膜综合性能最优。更多还原

【Abstract】 PI/SiO₂ hybrid films were prepared by sol-gel process.The effects of sol aging time on the properties of the PI/SiO₂ hybrid films were investigated using FT-IR ATR,SEM and TMA.The results show that as the hydrolysis and condensation taking place during aging of sol,the SiO₂ particles in hybrid films grow from ellipsoid to spheres,and agglomerate to bigger particles which makes the PI/SiO₂ films become opaque.As the diameters of SiO₂ particles grow,thermal expansion coefficient of the hybrid films decrease,the shrinkage and modulus increase while the tensile strength and elongation at break decrease after increasing.The hybrid films reach comprehensive properties when SiO₂ particles with diameter smaller than 1 μm uniformly disperse in matrix.更多还原