Self‐Healing Polyurethane Elastomers with Superior Tensile Strength and Elastic Recovery Based on Dynamic Oxime‐Carbamate and Hydrogen Bond Interactions

Abstract

AbstractThe preparation of self‐healing polyurethane elastomers (PUEs) incorporating dynamic bonds is of considerable practical significance. However, developing a PUE with outstanding mechanical properties and high self‐healing efficiency poses a significant challenge. Herein, this work has successfully developed a series of self‐healing PUEs with various outstanding properties through rational molecular design. These PUEs incorporate m‐xylylene diisocyanate and reversible dimethylglyoxime as hard segment, along with polytetramethylene ether glycol as soft segment. A significant amount of dynamic oxime‐carbamate and hydrogen bonds are formed in hard segment. The microphase separated structure of the PUEs enables them to be colorless with a transparency of >90%. Owing to the chemical composition and multiple dynamic interactions, the PUEs are endowed with ultra‐high tensile strength of 34.5 MPa, satisfactory toughness of 53.9 MJ m−3, and great elastic recovery both at low and high strains. The movement of polymer molecular chains and the dynamic reversible interactions render a self‐healing efficiency of 101% at 70 °C. In addition, this self‐healing polyurethane could still maintain high mechanical properties after recycling. This study provides a design strategy for the preparation of a comprehensive polyurethane with superior overall performance, which holds wide application prospects in the fields of flexible displays and solar cells.