Vitrimer-based thermosets: From dynamic chemistry to circular materials

Abstract

This work presents a systematic review on vitrimers, which are a category of dynamic covalent network polymer that possesses both the high thermal stability, mechanical resilience, and chemical resistance of traditional thermosets and the reprocessability and recyclability typical of thermoplastics. Vitrimers achieve these properties through associative covalent bond-exchange reactions, such as transesterification, disulfide reshuffling, and imine exchange, which allow network restructuring upon heating while maintaining cross-link density. The intrinsic dynamic nature of vitrimers leads to important capabilities such as self-healing, welding, shape-memory, and recyclability using thermal reprocessing, solvent-induced dissolution, and chemical depolymerization to yield monomers. While there are significant benefits associated with this class of materials, there are still some challenges associated with the use of vitrimers, such as reduced mechanical strength compared to high-performance thermosets and relatively high stress-relaxation times. Currently, research mainly focuses on molecular design approaches that incorporate nanofillers, develop more effective catalysts, and control bond-exchange kinetics to improve the thermal stability, strength, and relaxation dynamics of vitrimers. This work emphasizes that, given continuous development, there are areas where vitrimers could bring revolutionary changes, including transport (lightweight composites for automobiles, aerospace adhesives, and reparable structural materials), as well as sustainable technologies, namely recyclable electronics, wind turbine blades, and circular-economy approaches to the recycling of plastic waste.