| Although thermoplastic matrix composites are being proposed as a second generation of composite material for a number of advanced and high performance applications, little has been reported concerning the processing-structure-property relationships for either the newly developed matrix resins or their combination in the composite. The research described here involves such a study for a representative matrix resin, the J1-polymer (a polyamide) proposed by DuPont. The research was conducted in parallel with related studies, primarily by other personnel, of graphite fiber/J1-polymer unidirectional composites.;X-ray and transmission electron microscopy studies were conducted to examine the structure/morphology of the neat resin. Thermal analysis by differential scanning calorimetry was used to investigate the effects of different heating and cooling rates and various processing conditions. Dynamic mechanical properties of the neat resin were characterized. The fundamental mechanisms of deformation and failure, including creep, crack growth and fracture behaviors, were examined both at room temperature and at elevated temperature. A number of the techniques were extended to characterize the composite as well as the neat resin. The results are generic in the sense representing the types of studies needed to develop data to permit verification of appropriate analytical models and theories for thermoplastic-matrix fiber composites. |
