Optimal Preparation and Interface Strengthening of High‐Temperature Resistance Sizing Agents for Carbon Fiber Reinforced Poly(Ether Ether Ketone) Composites: A Mini‐Review

ABSTRACT

Carbon fiber reinforced polyetheretherketone (CF/PEEK) composites have attracted significant attention in recent years for use in large aviation structures, driven by the growth of green and sustainable aviation. These composites offer high toughness, fatigue resistance, long‐term stability, fast molding, and recyclability. However, the smooth surface and low surface energy of CF hinder effective impregnation by viscous PEEK resin, leading to poor interlaminar shear strength (ILSS). Based on the principle of like dissolves like, designing polymers with tailored molecular structures as sizing agents for CFs is an environmentally friendly and engineering‐feasible approach to improve interfacial bonding. However, conventional sizing agents, such as epoxy, polyurethane, and polyamide, degrade under the high temperatures and pressures of CF/PEEK processing, resulting in carbonization and weak fiber–matrix interfaces. This paper reviews factors affecting interfacial performance, common characterization and simulation methods, and focuses on advances in molecular design and synthesis of polyaryletherketone‐based and polyimide‐based sizing agents. It also discusses progress in multifunctional organic–inorganic hybrid sizing agents, compares lab‐scale fiber sizing with continuous industrial processes, and analyzes key factors influencing composite performance. Finally, the high‐performance and heat‐resistant sizing agents are promoted for the development and engineering validation, thereby accelerating the adoption of CF/PEEK composites in next‐generation green aircraft and power systems.