Hierarchically Interface‐Programmed Modified Polyurethane for Self‐Healing and Weather‐Resistant Protection

Abstract Developing multifunctional protective coatings with long‐term durability, UV resistance, and autonomous healing capability is crucial for addressing corrosion challenges in harsh service environments. Herein, a hierarchically interface‐programmed polyurethane composite coating is constructed by covalently grafting an antioxidant into the polymer backbone and embedding photothermal‐active polyacrylonitrile/cobalt–manganese–nickel layered double hydroxide (LDH) nanofibers via electrospinning and template etching. The antioxidant‐modified matrix suppresses photooxidative degradation, while the LDH nanofillers enable efficient solar‐to‐thermal conversion, ion trapping, and strong interfacial hydrogen bonding. These interfacial interactions created “rivet‐like” anchoring sites, significantly improving coating compactness and interfacial adhesion stability. The composite coating exhibited rapid and efficient solar‐triggered self‐healing, achieving self‐healing efficiency of 98.3% within 5 min illumination. Even after 360 h of UV aging, the coating retained high gloss, mechanical integrity, and self‐healing capability. Electrochemical analysis confirmed superior long‐term corrosion resistance. This work provides a molecular‐to‐hierarchical design strategy for durable, sunlight‐adaptive coatings with integrated self‐healing, anti‐aging, and anticorrosion functions, offering promising applications in marine, transportation, and outdoor infrastructure.