中文摘要：

采用湿法混合工艺制备了短切石英纤维增强的PMR型聚酰亚胺复合材料模塑粉，使用热模压一次成型技术制备了聚酰亚胺树脂基复合材料，对复合材料的性能进行了系统研究。研究结果表明：短切石英纤维增强的复合材料具有优异的热性能和良好的力学性能，纤维含量对复合材料玻璃化转变温度和热失重温度影响不大，对材料的力学性能影响显著。复合材料具有优异的介电性能，在1kHz～18GHz宽频范围内具有稳定的介电常数和介电损耗。

英文摘要：

The short quartz fiber reinforced polyimide composites （SQF/PI） were prepared by thermal curing of B-staged molding powders, which were obtained by impregnating of short quartz fibers with PMR monomer solution in ethyl alcohol followed by thermal baking up to 220℃. The experimental results demonstrate that the fully-cured SQF/PI composites exhibit high thermal stability and good mechanical properties, and the fiber content has little influence on the thermal property but great influence on the mechanical property. The SQF/PI composites show an excellent dielectric property, stable dielectric constant and dissipation factor in the broad frequency range from 1 kHz to 18 GHz.