Vitrimer Chemistry and Associated Challenges in Composite Applications

Vitrimers represent a ground-breaking advancement in polymer chemistry, bridging the gap between traditional thermosets and thermoplastics. Defined by their ability to undergo dynamic covalent bond exchanges, these materials offer a unique combination of robustness, reprocessability, and recyclability. This chapter describes the main vitrimer chemistries that have shown significant progress in the field of composites, including transesterification, disulfide exchange, vinylogous urethanes, and imine exchanges. Particular attention is given to the underlying exchange mechanisms, both associative and dissociative, and the complex interplay between catalyst selection, exchange reaction kinetics, network topology, cross-linking density, and the local chemical environment. These factors collectively determine the rate and efficiency of bond rearrangement, influencing key vitrimer properties such as stress relaxation, creep resistance, thermal stability, and overall reprocessability. The chapter also highlights how subtle changes in formulation, including stoichiometry and internal catalysis, can drastically alter vitrimer behaviour, highlighting the need of precise material design. By combining an in-depth overview of chemical versatility with a discussion of the processing challenges that remain, this chapter provides a balanced perspective on the current state of vitrimer-based composites and identifies the key opportunities and directions that will shape their future industrial adoption.