A review on the self‐healing ability of epoxy polymers

This review encompasses the research progress on self‐healing properties of epoxy polymers and is divided into two categories: material supplement and energy supplement. The central concept of material supplement revolves around the addition of functional composite materials, such as, hollow fiber and microcapsule, to repair the micro‐cracks of epoxy polymers. In contrast, the energy supplement is based on the concurrent incorporation of some functional groups into the thermosetting epoxy polymers. These functional chemical groups participate in the construction of a three‐dimensional network structure of thermosetting materials and successfully enter the block copolymer of epoxy polymers. When the micro‐cracks are developed in the resin upon exterior impact, these functional groups automatically absorb energy from the outside to perform chemical reactions and automatically repair their micro‐cracks following the self‐healing phenomenon. Five kinds of reversible reactions are introduced for energy supply and are discussed in detail. Finally, a summary and comparison of the self‐healing methods covered in this review and the application prospect of self‐healing epoxy polymers are summarized. The self‐healing properties of thermosetting materials have become a hot topic of research for many scientists. Therefore, this review encompasses the research progress on epoxy polymers' self‐healing properties and is divided into two categories: material supplement and energy supplement.