This work is aimed at presenting the synthesis of a poly (amic acid) (PAA) to be used as interphase precursor in the manufacturing of high performance thermoplastic composites. Thermoplastic composites comprising a rigid reinforcement and a ductile matrix have their mechanical properties strongly dependent on the load transfer mechanism between the reinforcement and matrix. For this reason, the interface/interphase region plays a fundamental hole in the final properties of the composite materials. PAA appeared as an alternative to improve the fiber/matrix adhesion when it is transformed in polyimide (PI) favoring the link between the reinforcement and the thermoplastic matrix. This work shows the PAA synthesis from BTDA and DHPr reagents and its conversion into PI by imidization in a liquid medium. Mass spectrometry analysis confirmed the synthesis of PAA from the precursor reagents and the FTIR analysis evaluated the success of the conversion of PAA into PI. DSC and TGA analysis of the PI determined their glass transition (~213 °C) and decomposition (~310 °C) temperatures, respectively. These results motivate the use of PAA/PI as precursor of interphase to obtain thermoplastic composites with processing temperatures below 310 °C.
Advanced composites; poly (amic acid); interface; interphase
