A Photohealable Polyurethane with Superior Robustness and Healing Ratio

Combining photohealing and reprocessing in covalent adaptive networks (CANs) offers a convenient healing condition and extended life span. Herein, we propose a strategy to fabricate photohealable polyurethanes (PHPUs) by molecule design. Benefiting from their permanent covalent crosslinking structure, PHPUs present superior mechanical robustness and high healing ratio; specifically, their tensile strength attains 36 MPa and toughness attains 86 MJ/m 3 . Furthermore, PHPU-3 exhibits an excellent healing ratio of 99%/94% under heat/photostimulation. Additionally, the shape programming of the PHPUs can proceed under the remote control of infrared (IR) light. The combination of the above performance provides PHPUs with a practical application prospect.