Boron-containing polymers have been used in many aspects because of their excellent properties. Molecules with reversible boronic ester bonds can be used to prepare various self-repairing polymers. The instability of boronic ester bonds after encountering water greatly restricted their further development. Herein, a self-healing polyurethane (BEN) containing nitrogen-coordinated cyclic borate diester (NCB) bonds is designed and synthesized based on the dynamic covalent borate and boron nitrogen coordination sharing method. With the help of synergistic cross-linking between molecules and intra-molecular folding, the self-healing polyurethane exhibits superior tensile toughness, outstanding tensile strength (55.45 MPa) and excellent breaking elongation rate(1021%). After N→B coordination is introduced, the stability and mechanical strength of the product has be significantly improved. BEN is equipped with good self-healing properties, of which the tensile strength can be restored to 14.7 MPa. Even if immersed in water at 60 <sup>o</sup>C for 24 hours, the self-healing polyurethane can still maintain strong mechanical strength. We hope this research could bring some guidance for the application of self-healing polyurethane in aerospace, intelligent manufacturing, 3D printing, and other fields.

Study of a self-healing polyurethane based on borate bond

Where thousands of chemistry professionals meet to share ideas and advance scientific and technical knowledge. Spring 2023 abstracts, posters, and presentations will launch at the end of March.

ACS Spring 2023

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.