Recent developments: self-healing polymers based on quadruple hydrogen bonds

The microcrack of materials was inevitable in the process of transportation, storage and utilization, which may cause functional failure and resources waste. Inspired by nature, self-healing polymers have attracted significant attention owing to widespread applications in wearable electronics, cartilage replacement, coatings and elastomer. Compared with extrinsic healing, intrinsically healable polymers offer multiple self-healing by supramolecular reversible interactions, such as host-guest interactions, π-π stacking, ionic interactions and hydrogen-bonding. Self-healing polymers based on quadruple hydrogen bonds have been extensively investigated due to its high thermodynamic stability and rapid kinetic reversibility, and have been well developed for the past two decades. In this paper, the strategies and designs of self-repairing polymers based on quadruple hydrogen bond were classified and summarized, including main-chain self-healing polymers, side-chain self-healing polymers and supramolecular self-healing polymers. It is expected that quadruple hydrogen bonding can be construct more robust, highly tough, multi-stimuli-responsive, and fast self-healing supramolecular polymer, and is potential to be applied to numerous civilian and military fields in the future.