Composites based on polyphtalamides matrices and continuous glass fibers: structure-processing and properties relationships

Abstract

Continuous Glass Fiber-Reinforced Thermoplastic Composites (GFRTC) were successfully prepared using two different routes: a reactive laboratory-created approach as well as a compression molding method. Two kinds of high-performance polyphtalamides (PPA) were studied: PPA from a chain extension reaction of its parent prepolymer (named R-PPA) in comparison with a virgin non-reactive PPA (NR-PPA). For the former, the chemo-rheological behaviors were investigated by coupling rheology with fast-scan and high temperature Fourier Transform InfraRed (FTIR) measurements. Interestingly, it was demonstrated that a maximum chain extension conversion could be obtained in a few minutes. Moreover, elevated molar masses could be reached with broad polydispersities. For thermo-compression forming process, and despite the moderate NR-PPA viscosity, it was therefore possible to obtain a good impregnation of the GFRTC with improved mechanical properties. By a subsequent thermal post-treatment, a correlation between the obtained highest glass transition temperatures (Tg), molar masses and induced crystallinities on thermomechanical properties could be emphasized. The present study thus highlights some interesting results to obtain structural heat-resistant GFRTC materials typically used in the field of aerospace and automotive parts intended especially for high service temperature applications.