Composites Based on Polyphtalamides Matrices and Continuous Glass Fibers: Rheology- Processing and Properties Relationships

Abstract Continuous Glass Fiber-Reinforced Thermoplastic Polymers (GFRTP) 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 in comparison with a virgin non-reactive reference (NRR) matrix. 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. Furthermore, a maximum glass transition temperature of 120 °C was revealed with a large rubbery plateau. By optimizing some experimental conditions (filling and reaction times, temperature), high thermomechanical properties were obtained especially with GFRTPs. For the NRR matrix, it was also possible to improve 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 high-quality GFRTP parts intended especially for high service temperature applications such as in the automotive or aerospace industries.