Synergistically Improved Interlaminar Fracture Toughness and Thermal Properties of <scp>CF</scp>/<scp>EP</scp> Composites With <scp>PEEK</scp> and <scp>MWCNTs</scp> Interleaves

ABSTRACT The low interlaminar fracture toughness and thermal properties of carbon fiber/epoxy resin (CF/EP) composites limit their applications in harsh environments. Synergetic improvement of the interlaminar fracture toughness and thermal conductivity of CF/EP is a challenging research job. In this paper, the surface of CF/EP prepregs was coated by multiwalled carbon nanotubes (MWCNTs) and PEEK, and then the modified CF/EP laminates were prepared by compression molding process. The effects of MWCNTs and PEEK on the mechanical properties and thermal properties of CF/EP laminates were investigated. The results showed that the type II interlaminar fracture toughness, impact strength, and thermal conductivity of the CF/EP laminates synergistically modified by 0.5 wt% MWCNTs, and 2 wt% PEEK reached 1404 J/m 2 , 277 J/m 2 , 0.89 W·m −1 ·K −1 at 100°C, which were 81%, 42% and 82% higher than that of unmodified CF/EP laminate, respectively. And thermal stability of CF/EP laminate was improved. The addition of MWCNTs and PEEK reduces the loss factor of CF/EP laminates. This work is of great significance to realize the integration of structure and function of composite materials in the high‐performance applications.