Progress in recyclable bio-based polymers based on dynamic covalent cross-linking chemistry

Presented in this review is the progress in the field of recyclable bio-based polymer materials based on dynamic covalent chemistry. It begins by introducing the fundamental concept of vitrimers and their role as a bridge between thermoplastic and thermosetting materials, elucidating the key mechanisms by which dynamic covalent bonds enable functionalities such as self-healing, reprocessability, shape memory, and closed-loop recycling. Subsequently, the design principles and application fields of various dynamic covalent bonds in bio-based polymers are summarized, including their structural characteristics, response mechanisms, and performance advantages, with a detailed discussion on cutting-edge developments in dual dynamic network strategies for enhancing comprehensive material properties. Furthermore, practical application cases of such materials in areas including shape memory polymers, high-performance plastics, polymer membranes, three-dimensional (3D) printing, adhesives, and biomedical materials are reviewed. Finally, the current research challenges are analyzed, and future development directions are outlooked.