Preparation and properties of chopped quartz f iber/ PMR polyimide composites

The short quartz f iber reinforced polyimide composites (SQF/ PI) were prepared by thermal curing of B-stagedmolding powders , which were obtained by impregnating of short quartz f ibers with PMR monomer solution in ethyl alcoholfollowed 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 f iber content has little influence on the thermal propertybut great influence on the mechanical property. The SQF/ PI composites show an excellent dielectric property , stabledielect ric constant and dissipation factor in the broad f requency range from 1 kHz to 18 GHz.