Conventionally facile fabrication of mechanically robust waterborne polyurethane with self‐healing and photoluminescence

Abstract It is of much importance to synthesize waterborne polyurethane (WPUs) that simultaneously broaden the fields of applications and functions in a green strategy. In this paper, a novel class of WPUs were facilely prepared through the copolymerization between polytetrahydrofuran ether diol (PTMG), isophorone diisocyanate, and 2,2‐bis(hydroxymethyl)propionic acid, which can achieve multiple functions of self‐healing and photoluminescence after incorporating carbon quantum dots (CQs) into the WPUs. The prepared WPUs emulsion showed uniform size distribution from 61.97 nm to171.3 nm with different PTMG molecular weights. Especially, the maximum tensile strength and elongation at break of the WPUs can reach up to 69.78 MPa and 1879.99%, showing superior mechanical performance. After fractured surfaces held contact for 12 h at elevated temperature, the self‐healing efficiency of the pristine WPUs can reach 21.39% for tensile strength and 24.79% for elongation at break. After adding CQs, the synthesized WPUs can also remain nearly the same tensile strength and elongation at break. Significantly, the self‐healing WPUs with CQs can emit a bright orange fluorescence under ultraviolet light, showing outstanding photoluminescence. This kind of designed material takes advantages of simple preparation, no release of organic solvents during use, nontoxicity and harmlessness.