Matrix resin improvement for aerospace polymer matrix composites

A promising thermoplastic modified epoxy system has been developed at LAC to meet the aerospace specific requirements such as good impact and hot/wet behavior, and high damage tolerance as well. The thermoplastic modifier was PEK-C, a domestic product in China. The processing-structure-property relations for the resin casts and carbon composites were studied in terms of composition, morphology, inter-phase reaction, and mechanical properties. To explore the organoclay also as a possible modifier for polymer matrix resins, intercalation and exfoliation behavior were studied by using XRD and DSC, respectively. Subsequently, exfoliated organoclay/epoxy nanocomposites have been prepared. The exfoliation ability was basically determined by the nature of the clays and the curing agent used. Factors affecting the exfoliation and mechanical properties of the composites were also discussed. Also successfully developed at LAC was a composition-modified, one part BMI system with quite low viscosity and long pot lif e, suitable for RTM. The system exhibits balanced processing ability and hot/wet behavior, combined with a good mechanical property profile, meeting the typical requirements for RTM processed aerospace structures.