Enhancing the mechanical properties of self‐healing polyurethane via chemical crosslinking

Abstract Self‐healing research based on commercial polymeric materials (such as polyurethane) is beneficial to sustainable development by prolonging the life of materials. However, developing polymeric materials that integrate robust mechanical properties with self‐healing ability at ambient temperature remains a formidable challenge. The formation of polymeric materials by physically and chemically dual crosslinking structures is a powerful method to improve mechanical properties. Herein, a series of dual crosslinking self‐healing polyurethane have been designed and successfully synthesized by incorporating 2‐ureido‐4[1H]‐pyrimidinone (UPy) units and triethanolamine (TEOA) into the polymer networks. Relying on the reinforcement of chemical crosslinking which is induced by TEOA, the resulting polyurethane exhibited robust strength of 10.3 MPa and elongation at break of 569.4%, which are quite prominent compared with previous reports. At the same time, the recombination of hydrogen bonds makes the polyurethane with UPy structure achieve rapid self‐healing after 24 h at 40°C and the strength recovered to 4.98 MPa. This work provided a novel way to fabricate sustainable polyurethane with robust mechanical properties.