Multistimulus Responsive High-Strength Self-Healing Polyurethane Based on Rhodamine and Multiple H-Bonding

The capacity for environmental adaptation in biological systems is achieved through the optimized functionality of three mechanisms: the structural reinforcement of materials, self-healing capabilities to repair damage, and adaptive coloration for effective camouflage. Nonetheless, integrating all three properties into a single material remains extremely challenging. Herein, a polyurethane elastomer (RGPU3.5–75) featuring multistimulus responsive abilities, high mechanical strength, and self-healing properties was synthesized using bis(hydroxymethyl) rhodamine 6G (RG2OH) as a color-changing monomer. The material RGPU3.5–75 exhibits rapid discoloration behavior under UV light, stretching and acidic conditions, shape programming in response to thermal stimuli, as well as excellent mechanical strength (55.1 MPa) and self-healing efficiency (90.7%). The structural designs will pave the way for the development of multistimulus responsive materials and their application in harsh environments.