High-Performance Cross-Linked Self-Healing Material Based on Multiple Dynamic Bonds

Abstract

There is a trade-off between mechanical and self-healing performance for cross-linked self-healing materials. Herein, we design a polyurethane material containing triple synergy dynamic bonds to address the dilemma. The as-prepared polyurethane exhibits a maximum stress of 27.3 MPa and excellent self-healing performance. Specifically, boric acid is used as a cross-linker and the network cross-linked with boronic ester bonds under alkaline conditions is highly beneficial in terms of mechanical properties. Meanwhile, disulfide bonds and reversible boronic ester bonds located at the cross-linked point and main chain are successively broken upon being damaged, which is conducive to better fluidity of chains and endows the material with superior healing efficiency and multiple cycles of healing. Consequently, the high-performance self-healing material is of great potential in the fields of high-performance coating, aerospace, and load-bearing rubber.