Ultra-robust, highly stretchable and ambient temperature rapid self-healing polyurethane/graphene elastomers enabled by multi-type hydrogen bonds

Abstract

Artificial elastomers with self-healing functions are favored for their ability to repair damaged defects. However, balancing their mechanical strength, stretchability, and fast room temperature self-healing ability can be a significant challenge. Herein, this study presents a robust and highly stretchable self-healing elastomer with a spider-silk-like and inverse artificial nacre structure based on a nucleobase non-covalent assembly. Specifically, thymine-containing side chain hydrogen (H)-bonds and high-density sextuple H-bond arrays are introduced within polyurethanes to improve the kinematic activity of molecular chains and regulate the mechanical properties. Adenine-modified graphene oxide nanosheets are embedded into these elastomers to provide abundant interfacial non-covalent H-bonds. The multi-type H-bond synergy effectively resolved the abovementioned contradicting characteristics, creating an elastomer with the best reported mechanical properties (excellent strength of 46.60 MPa and stretchability of 1736.89%) within 2 h of room temperature self-healing (self-healing efficiency = 85.62%). Interestingly, the bionic polyurethane/graphene demonstrated anti-corrosion and crawling functions for rapid self-healing even in low-temperature and aqueous environments, providing a new strategy for the construction of tough self-healing flexible composites.