A Multifunctional Biomass Zinc Catalyst for Epoxy-Based Vitrimers and Composites

High catalyst loading is often required in the preparation of epoxy-based vitrimers. This may lead to catalyst migration, pollution, and a decrease in mechanical properties. In this contribution, a biomass zinc carboxylate (EP-Zn) derived from the epoxide of 10-undecenoic acid is used as a multifunctional catalyst in the synthesis of bisphenol A-epoxy-based vitrimers. The zinc ions can catalyze curing, transesterification and hydrolysis (degradation) reactions of polyester epoxy resins. More importantly, the zinc carboxylate no longer exists in the free state but becomes part of the crosslinked network, leading to significant enhancement of the tensile properties via the formation of supramolecular ionic clusters. Moreover, the amphiphilic structure of this long-chain zinc carboxylate allows it to be used as a compatibilizer for vitrimer-based composites, enabling improved tensile strength.