Hydrogen-bond network reconstruction driven transparent α-chitin polyurethane coatings for eco-friendly surface protection: Synergistic antifouling and anticorrosion enhancement

α-Chitin, as a natural bio-based polyol, possesses significant potential in bio-based green coatings. However, its intractable solubility and poor processability resulting from robust intermolecular hydrogen bonding and high crystallinity have long impeded the development and application of high-performance, environmentally friendly biomass coatings. To address this challenge, we propose a novel “hydrogen-bond network reconstruction” strategy. Through physicochemical co-modification disrupting chitin's microstructure, we successfully overcame its solubility barrier. Using this highly soluble chitin as the matrix and integrating flexible polydimethylsiloxane (PDMS) with hexamethylene diisocyanate trimer (HDIT) crosslinking technology, we fabricated an omniphobic coating with exceptional comprehensive properties. This coating exhibits an ultra-low surface energy (17 mJ·m −2 , lower than PTFE) and a densely cross-linked network, demonstrating not only superhydrophobicity/superoleophobicity with high contact angles (water: 110.7 ± 0.8°, diiodomethane: 80.9 ± 1.9°), excellent self-cleaning capability, and efficient anti-fouling/anti-graffiti properties, but also, owing to its reinforced network structure, remarkable mechanical stability (6H pencil hardness, A1-grade adhesion, abrasion resistance) and chemical resistance (tolerance to chemical agents, no corrosion after 10-day saline immersion, 20-fold reduction in corrosion current density ( I corr ) compared to bare iron). Simultaneously, it maintains high optical transparency (95 %). This coating provides a green, durable, and easy-to-maintain protective solution for precision devices such as electronic displays and solar panels, significantly extending service life while reducing cleaning energy consumption. This work establishes a foundation for developing high-performance biomass coatings integrating both ecological sustainability and industrial value via “hydrogen-bond network reconstruction” and green manufacturing pathways.