• Solution impregnation enables uniform and complete filling of CF bundles with PEKK, achieving high interfacial and interlaminar shear strengths (IFSS 107.8 MPa, ILSS 99.3 MPa).
• The amorphous PEKK interface formed in confined spaces between carbon fibers is key to superior shear performance, outperforming CF/epoxy interfaces by over 40%.
• The method uses a mixed solvent (4-chlorophenol and 1,2-dichloroethane) to achieve excellent wettability and tight binding of PEKK to CF surfaces.
• This approach offers a promising alternative to traditional melt processing for high-performance thermoplastic composites, addressing challenges of poor melt fluidity and inertness.