Cation‐π Interaction‐Driven Polyurethane Material With Superior Seawater Resistance and Excellent Tribological Performance

ABSTRACT Factors such as high humidity and salinity in the marine environment can accelerate material corrosion and wear. Achieving multiscale synergistic optimization of excellent mechanical and tribological properties of materials in the marine environment remains a critical scientific challenge that requires urgent resolution. To tackle this issue, we strategically incorporated a cation‐π interaction‐enhanced mechanism into the backbone structure of polyurethane via “molecular engineering”, creating a functionalized material system with inherent seawater resistance and excellent tribological properties. Here, the introduction of cation‐π interactions into a polyurethane (PUNa) network induces the formation of hydrogen‐bonded nanodomains, effectively shielding hydrogen‐bond from corrosive attack in seawater and endowing the material with exceptional adaptability to the marine environment. Notably, after seawater immersion, the elastomer exhibits a remarkable toughness of 205.4 MJ·m − 3 (1.19 times the original value) and superior tribological performance, with the coefficient of friction (COF) reduced by 38%. Furthermore, by combining molecular simulation with experimental analysis the underlying mechanisms governing its superior seawater resistance and tribological behavior are systematically elucidated, providing a solid foundation for its application in deep‐sea equipment.