High Stretchability and Elastic Self-Healing Polyurethane Elastomer through Dual Cross-Linking with Metal–Ligand Coordination and Hydrogen Bonds

Abstract

Herein, a high stretchability and elastic self-healing (SH) polyurethane elastomer is designed by introducing the ligand PDs with two hydrazides and one pyridine into the IPDI-type polyurethane elastomer backbone, which can guarantee the synergistic interplay of multiple dynamic bonds including abundant hydrogen bonds, strong cross-linking H-bonds (PDs−PDs), weak cross-linking H-bonds (urea and amine−ester bonds, etc.), and metal coordination bonds (PDs−Ce). The introduction of these dynamic bonds not only confers excellent SH properties but also enhances the mechanical characteristics of the material. The elastomer exhibits a remarkable tensile strength (11.3 MPa), exceptional stretchability (1336%), and high toughness (82.6 MJ m −3 ) as well as an impressive healing efficiency (η H ) reaching 91% after 24 h at ambient temperature. These characteristics are linked to the synergistic interplay of the weak H-bonds, dynamic strong bonds, and the metal−ligand bonds (PDs−Ce). Besides, the elastomer was applied in balloons, self-repairing tires, and membrane material, all of which show better performance, thus confirming the viability of the material as a high-performance SH elastomer material for various applications.