Devolatilization in the processing of AFR700B polyimide resin composites

摘要

During the processing of condensation polyimide composites, prepregging solvent, volatile by-products of the condensation reaction and environmentally absorbed water are the primary causes of voids in laminates. Avoidance of this problem requiresproper process simulation models and adequate sensing technology.A model describing the devolatilization of polyimide composites was expanded to accommodate additional polyimide systems like AFR700B. The model was experimentally verified and together with dynamic dielectric measurements was used to study thepolyimidization (polycondensation) reaction and accompanying devolatilization process for unidirectional AFR700B/S-2 glass laminates. For the first time it was possible to explain the dielectric sensor measurements in real processing cycles and selectproper temperature-pressure-time relations for optimal autoclave processing of this polyimide resin system.