Research on Self-healing Polypolyurethane Elastomer Based on Multiple Reversible Action

Self-healing materials received widely concerns because of its ability f'or prolonging the service life of materials and fulfilling the need 'kw sustainable development in recent years. To solve the problem that self-healing materials can' t do both well in self-healing property and mechanical property, we prepared a self-healing polyurethane elastomer with high strength, high toughness and high repair efficiency in this paper, on the basis of the designability of polyurethanes , we introduced disulfide bond to the polyurethane main chainis and used boric acid ester bond constructed using boric acid as a reversible cross-linking point to form the cross-linked network structure. The materials was characterized by infrared spectroscopy, dynamic mechanical analysis, mechanical test, electron microscope and self-healing test. The results show that the self-healing polyurethane has the characteristics of hard and tough , which the strength of the original sample has 23. 3 MPa , the elongation at break can reach 11. 77%, and can self-heal at a mild conditions. After repairing at 60 degrees C for 24 h , the original strength of the sample can be restored to 99% , and the self-healing process can be repeated many times. In addition, the material has the characteristics of multi-channel self-healing, which can be repaired by means of thermal self-healing or water-assisted thermal self-healing, and the latter is faster.