Enhancing the processability and interfacial adhesion of CF/PEEK composites with hyperbranched polyimide

The mechanical properties of CF/PEEK composites are limited by the poor interfacial adhesion between PEEK and CF. Hyperbranched polyimide (HBPI) was synthesized as a new modifier to improve the mobility of PEEK, and then CF/HBPI/PEEK were fabricated. The decomposition temperature of HBPI was increased by reducing the proportion of triazine ring. By mixing HBPI and PEEK, the melt flow rate (MFR) of PEEK was increased by up to 20%, and the mechanical properties of CF/HBPI/PEEK composites were also significantly improved while less interface debondings between PEEK and CF were found in the fracture morphology. The above results suggested that the wettability and interfacial interaction between PEEK and CF could be improved by HBPI, indicating that HBPI could serve as a suitable modifier for CF/PEEK composites.