Designing Ambient Self‐Healing, Anticorrosive, Transparent, and Resilient Hydroxyl Terminated Polybutadiene Based Polyurethane Coatings: Beyond One Dynamic Mechanism

ABSTRACT Despite numerous application domains, the disposal of conventional thermoset polyurethanes (PUs) poses a significant challenge to achieving sustainable development in the next generation. Designing multifunctional polymeric elastomers with self‐healing and anti‐corrosive capabilities is essential for extending service life in demanding environments. In this study, we report the development of a novel hydroxyl‐terminated polybutadiene (HTPB) based self‐healing polyurethane elastomer (SHPUE) that incorporates dynamic covalent and supramolecular interactions to achieve robust mechanical strength, excellent flexibility, transparency, anticorrosion properties, and autonomous healing at ambient temperatures. The SHPU network was synthesized using the pre‐polymer method at a slightly higher stoichiometric NCO/OH of 1.05, employing HTPB as macrodiol, isophorone diisocyanate as curing agent, with 2‐hydroxyethyl disulfide (HEDS) as chain extender, trimethylolpropane tris(3‐mercaptopropionate) as a crosslinker, and ZnCl 2 solution to form a metal coordination bond. Fourier transformation infrared spectroscopy and Raman spectroscopy confirmed successful polymerization to yield urethane linkages and integration of thiourethane, disulfide, and Zn 2+ N/Zn 2+ O linkages. X‐ray photoelectron spectroscopy revealed Zn 2+ –N coordination at 400.2 eV. Thiourethane linkages, disulfide reshuffling, and reversible Zn 2+ coordination enable efficient self‐repair under ambient conditions. Mechanical tests demonstrated greater than 90% healing after 24 h. Stress relaxation showed delayed topology freezing. SHPU‐0.40 exhibited enhanced salt spray resistance and greater than 80% transmittance. These results highlight a promising strategy for tunable, sustainable polyurethane coatings with self‐healing and protective functions.