Strong and Tough Self-Healing Elastomers via BTA-Mediated Microstructure and Metal-ligand Coordination.

Abstract

Creating elastomers with high strength, toughness, and rapid self-healing remains a key challenge. These seemingly contradictory properties require innovative design strategies. Herein, a novel approach is proposed by simultaneously incorporating a unique triple hydrogen bond unit, benzene-1,3,5-tricarboxamide (BTA), and imidazole-Zn²⁺ dynamic coordination into the elastomer. The BTA forms rigid fibers through self-assembly via triple hydrogen bonding, inducing microphase separation that significantly enhances the material's properties. Hydrogen bonds and coordination interactions provide dynamic reversibility and self-healing, achieving a balance of strength, toughness, and healing capabilities. By varying the BTA content and the degree of coordination crosslinking, the elastomer's strength is tunable within 8.79-2.03 MPa, and it boasts an impressive elongation at a break of up to 700%. Remarkably, it recovers 94.6% of its strength after being cut in half, facilitated by treatment with DMF at 70 °C for 24 h. Furthermore, the integration of carbon nanotubes endows the material with resistance-sensing, enabling real-time monitoring of human movements. Overall, this study lays a theoretical foundation and introduces innovative concepts for the development of high-toughness self-healing elastomers.