Construction of CF@ZIF-67 Reinforcements with a Polyphenol-Based Interlayer for Enhanced Interfacial Properties of PPESK Composites

This study provides a novel strategy for improving the interfacial properties of advanced thermoplastic composites. Metal-organic framework (MOF) materials exhibit significant potential in enhancing the interfacial properties of composite materials due to their special structure and extremely high specific surface area. However, existing introduction methods relying on pre-acidification treatments can impair the mechanical properties of carbon fibers (CFs) and lead to issues such as uneven growth of MOFs. This paper utilizes resveratrol (RES) in reaction with hexachlorocyclotriphosphazene (HCCP) and bisphenol S (BPS) to construct a polyphenol cross-linked coating on the surface of CFs. The coating provides excellent heterogeneous nucleation sites for ZIF-67 without the need for pre-acidification, successfully enabling the loading of MOF on the fiber surface. Compared to unmodified composites, the interlaminar shear strength (ILSS) and flexural strength of CF@ZIF-67/ polyphthalazine ether sulfone ketone (PPESK) increased by 32.44% and 29.62%, respectively. The storage modulus reached 42 GPa, and the glass transition temperature rose to 298°C. Fracture morphology analysis further revealed that the failure mode shifted from interface debonding to resin cohesive failure, demonstrating a substantial enhancement in interfacial bonding.