Optimal Preparation and Aging Resistance Mechanism of High‐Temperature‐Resistant Carbon Fiber/Polyimide Resin ( CF / PI ) Composites for Advanced Aviation: A Short Review

ABSTRACT Carbon fiber‐reinforced polyimide (CF/PI) composites are lightweight, strong, designable, and heat‐resistant, making them ideal for aircraft structures. As flight speed and altitude increase, so does in‐flight temperature, demanding better high‐temperature and aging resistance, especially under high‐energy radiation at high altitudes. Conventional PI resins struggle to balance thermal stability with processability. Research has mainly focused on improving interfacial heat resistance, but lacks insight into interfacial thermo‐mechanical stress transfer under high temperatures. Enhancing the heat resistance of PI matrix through synergistic optimization of monomers, end‐capping agents, and curing networks, and improving interfacial stress transfer at elevated temperatures are critical to maintaining composite performance. Moreover, PI exhibits excellent resistance to aging due to its aromatic and imide backbone. However, increasingly harsh aerospace environments require a deeper understanding of aging mechanisms and structure–property relationships. This paper reviews strategies for optimizing high‐temperature‐resistant PI resins and CF/PI interfaces, summarizes advances in monomer and end‐capper design, and examines curing network regulation. It also analyzes aging modes and mechanisms in aerospace applications, aiming to support broader use of CF/PI composites in high‐temperature, long‐life aviation structures.