Synthesis of self-healing supramolecular waterborne polyurethane with quadruple hydrogen bonds via ureidotriazine

A supramolecular waterborne polyurethane (SWPU) with excellent mechanical and self-healing properties simultaneously is reported in this work. Herein, the SWPU were synthesized by using 2,4-diamino-6-undecyl-1,3,5-triazine react with isophorone diisocyanate to introduce ureidotriazine (UTr) structures into the main chain of polyurethane that can self-assemble to form quadruple hydrogen bonds systems. A higher dimerization constant obtained through introducing two intramolecular hexatomic ring hydrogen bonds into the UTr structure, and the hydrophobicity, plasticity brought by the undecyl group on the triazine ring are beneficial to make a great balance between the binding strength for mechanical performance and the chain reversibility, mobility for self-healing. Owing to the accuracy design, the SWPU exhibits high tensile stress (33.85 MPa) and excellent self-healing ability (90.52%), which shows an enormous application potential in the field of functional coatings and adhesives.