An effective approach for the preparation of epoxy vitrimers by in situ formation of dynamic and permanent linkages in a one-pot curing reaction

This work reports a catalyst-free epoxy vitrimer, which was prepared using one-pot thermally-induced reactions similar to the conditions applied to conventional epoxy resins. With a Meldrum's acid functionalized aniline compound (MAMA) as a curing agent for the epoxy compounds, in situ formation of dynamic ester bonds and permanent tertiary amine linkages in the crosslinked networks are achieved by using ketene/–OH and amine/epoxy addition reactions, respectively. The tertiary amine groups have a significant catalytic effect on the transesterification of the dynamic ester bonds, meaning that the vitrimer could be recycled and reprocessed without additional catalysts. Moreover, the thermal and mechanical properties of the vitrimer are comparable to the properties of the conventional aromatic amine-cured bisphenol-A epoxy resin. Both the preparation conditions and properties of the obtained vitrimer are comparable to the conventional epoxy resins.