Karle, M. et. al.; Polym. Sci. Technol., 2025, https://pubs.acs.org/doi/10.1021/polymscitech.5c00118
We here report latent catalysts for a thermally triggered transesterification in polyester vitrimers, enabling a triggered dynamic bond exchange using N-heterocyclic carbenes (NHC–CO₂) and the organic amine salts, triazabicyclo[4.4.0]dec-5-ene (TBD) methanesulfonic acid (MSA), TBD:MSA. These catalysts are inactive under service conditions but active at elevated temperature or shear enable reversible covalent bond exchange. Mechanical testing after repeated cycling of the vitrimer confirmed that both pristine (E = 0.03 MPa) and reprocessed (E = 0.11 MPa) samples retained tensile properties so demonstrating efficient recyclability.