A Visible Light-Responsive, Fast Room-Temperature Self- Healing, Mechanically Robust, Antibacterial Waterborne Polyurethane Based on Triple Dynamic Bonds

Despite the recent rapid advancements in room-temperature self-healing waterborne polyurethanes, imparting fast self-healing ability while concurrently maintaining robust mechanical performance of waterborne polyurethanes remains a formidable challenge. Herein, we propose a molecular structure design strategy for developing visible light-responsive, room-temperature self-healing, and antibacterial waterborne polyurethane (DMZWPU) containing triple dynamic bonds of diselenide bonds, multiple hydrogen bonds, and Zn(II)–carboxylate coordination bonds. This innovative approach effectively balances the tensile stress, fracture toughness, and self-healing ability of the material. Thanks to the synergy of the three dynamic bonds, the resulting DMZWPU film demonstrates a tensile stress of 40.32 MPa and a fracture toughness of 119.29 MJ/m 3, respectively. Furthermore, based on the dynamic characteristics of three dynamic bonds and the dual induction of trace ethanol and visible light, the damaged DMZWPU film can recover more than 85% of the tensile stress at room temperature within 2 h. These performances outperform those of most of the currently reported room-temperature self-healable polymers (healing efficiency >80%). Due to the combined action of selenium and zinc ions, the DWZWPU film exhibits excellent antibacterial properties (sterilization rate of 100% in 24 h). Finally, the DMZWPU emulsion is effectively applied for leather finishing processes, and the results show that the DMZWPU coating exhibits excellent folding resistance, wear resistance, and room-temperature self-healing function, as well as enhanced water resistance and dry friction resistance. In summary, this study provides a novel perspective for the development of waterborne polyurethane with high mechanical performances and rapid self-healable ability at room temperature.