Sustainable and Reprocessable Epoxy Resins Utilizing Vanillin-based Schiff Base Chemistry: A Mini-Review

Epoxy resin, a thermosetting polymer, is widely used across industries for its exceptional mechanical strength, heat resistance, and chemical stability. However, traditional epoxy derived from petroleum is not recyclable or remoldable, which limits its sustainability. To address these limitations, researchers have developed recyclable and reprocessable epoxy materials. Vanillin, a naturally occurring compound, has emerged as a promising alternative. Vanillin reacts with amines to form imine bonds, which serve as the foundation for reprocessable epoxy resins. These resins can be produced using vanillin either as a monomer or as a hardener. This review highlights recent advancements in the application of vanillin for these purposes, emphasizing the role of Schiff base mechanisms. The discussion begins with an overview of dynamic covalent bonds, particularly Schiff bases, in reprocessable epoxy systems. It further explores how vanillin derivatives function as monomers or hardeners in the development of epoxy vitrimer. Finally, the review addresses potential challenges and opportunities in utilizing vanillin for sustainable epoxy resin production. In the future, the research on vanillin-based epoxy vitrimer should focus on improving its stability and mechanical properties, optimizing its scalability, and assessing its environmental impact to advance sustainable materials and the circular economy.