Covalently anchored chromatic waterborne polyurethane with intrinsically dual-dynamic self-healing network for durable and colorfast textile coatings

To address the critical challenges associated with the practical application of traditional dye molecules on fabric surfaces, including dye migration, insufficient colorfastness and the spontaneous microcracks that significantly impair the color integrity and aesthetics, a series of chromatic waterborne polyurethane (WPU) were designed and synthesized with a dual dynamic self-healing system. Sudan black B as color molecular moiety were covalently bonded to WPU backbone and could effectively inhibit migration dye migration and demonstrated excellent colorfastness. More notably, the synergistic network from dynamic covalent bond of bis(2-hydroxyethyl) disulfide (HEDS) and non-covalent crosslinking via 2,6-diaminopyridine (DAP)/iron coordination could enabled chromatic WPU self-healing performance. At room temperature, the scratches on the chromatic WPU film surface could self-healed within 30 min and the damage to the chromatic WPU-coated fabric was nearly restored 100% in an hour. This dual dynamic strategy resolved key issues of dye stability, colorfastness and self-healing and offered a novel approach for sustainable coloring materials in textile and functional coatings.