以原位分散聚合法制备出纳米碳化硅/聚酰亚胺(n-SiC/PI)复合薄膜,采用SEM、热机械分析仪(TMA)、阻抗分析仪和热重分析(TG)研究了所制备薄膜的表面形貌、热膨胀、介电性能及热稳定性。结果表明:SiC粒子均匀分散在PI基体中,复合薄膜的热膨胀系数(CTE)随着SiC含量的增加逐渐减小,SiC质量分数为15%时,CTE降低了11%,且复合膜的热膨胀系数实验值比较接近于Kerner公式的计算值。复合膜的介电常数和介电损耗随着填料含量的变化而变化,但始终维持在较低的范围内,并在相当大的频率范围内保持稳定。 The nano-SiC / polyimide (n-SiC / PI) composite films were prepared by in-situ dispersion polymerization. The mechanical properties of the composite films were investigated by SEM, TMA, Preparation of film surface morphology, thermal expansion, dielectric properties and thermal stability. The results show that the SiC particles are uniformly dispersed in the PI matrix. The CTE of the composite films decreases with the increase of the SiC content. When the SiC content is 15%, the CTE decreases by 11%. The thermal expansion coefficient The experimental values ​​are close to the calculated value of Kerner’s formula. The dielectric constant and dielectric loss of the composite films vary with the filler content, but remain within the lower range and remain stable over a wide range of frequencies.