Review of intrinsically recyclable biobased epoxy thermosets enabled by dynamic chemical bonds

Epoxy thermosets are usually dependent on fossil fuel-based resources, commonly diglycidyl ether bisphenol A (DGEBA) type epoxy monomers. However, the majority of these thermosets are toxic and nonrenewable, and their eternal cross-links make them difficult to reuse, reshape, and recycle. Because of the need to reduce greenhouse gas emissions and large amounts of irreversible thermoset waste, the design of biobased epoxy thermosets to replace petroleum-based thermosets and introduce dynamic bonds to thermosets. Moreover, destroyed thermosetting materials can be recovered, their service lifetime can be extended, and thermoset garbage will be abridged. It is also important to make them recyclable. This review article aims to outline the most recent and significant improvements in biobased epoxy thermosets that are intrinsically recyclable. First, the background and distinguishing characteristics such as repairability, recyclability, and reprocessability of dynamic covalent networks of recyclable thermosets are briefly discussed. Subsequently, the present paper reviewed the in-depth synthesizing, recycling and thermomechanical properties of partially biobased and fully biobased thermosetting materials derived from epoxy monomers and hardeners. Finally, the review highlights the opportunities and challenges of biobased inherently recyclable epoxy thermosets for future development.