Preparation of Nanotubes Grafted by Resin Matrix and Its Effect on the Mechanical Properties of Carbon Fiber Reinforced Poly(Bisphthalazinone Ether Sulfone Ketone) Composites

Multiwalled carbon nanotubes (MWCNTs) have demonstrated considerable potential for enhancing the mechanical performance of carbon fiber-reinforced high-performance thermoplastic polymer (CFRHPTP) composite. However, due to their tendency to aggregate within the thermoplastic matrix, overall performance improvements are limited. In order to address these issues, MWCNTs grafted with poly(bisphthalazinone ether sulfone ketone) (PBPESK@MWCNTs) were prepared by a diazotization reaction and then introduced into carbon fiber reinforced PBPESK (CF/PBPESK) composite laminates by dispersion in resin solution, which was immersed by CF to prepare prepregs, followed by a vacuum hot-pressing process. The structural and morphological characterization of PBPESK@MWCNTs was performed by Fourier transform infrared spectroscopy, Raman and X-ray photoelectron spectroscopy spectra, scanning electron microscopy (SEM), and transmission electron microscopy. The storage modulus and glass transition temperature of CF/PBPESK composites have been improved to 146 GPa and 322°C, respectively. Furthermore, the flexural strength, flexural modulus, and interlaminar shear strength of PBPESK@MWCNTs/CF/PBPESK composite were increased by 42.3%, 44.6%, and 42.9%, up to 1696 MPa, 162 GPa, and 70 MPa, respectively. Finally, the mechanism of reinforcement of composites by the introduction of PBPESK@MWCNTs has been revealed by SEM. Overall, this study highlights the potential of high-performance thermoplastic polymer-grafted MWCNTs as a strategy to enhance the mechanical performance of CFRHPTP composites to meet the application requirements.