Study on the Triethanolamine-Induced Enhancement of Hot-Press Recycling Performance in an Epoxy Vitrimer System

Epoxy resin is widely used in electrical and electronic applications because of its excellent electrical insulation and mechanical strength. However, its three-dimensional crosslinked network makes end-of-life components difficult to recycle. Reprocessable thermosetting epoxy resins (vitrimers) provide a pathway toward circular utilization but still suffer from incomplete interfacial healing and property deterioration during hot-press recycling. To enhance recycled-material performance, this study proposes a triethanolamine (TEOA)-induced interfacial reinforcement strategy. The results demonstrate that TEOA reduces the transesterification energy barrier and accelerates interfacial network reconstruction by forming multiple hydrogen bonds with pendant hydroxyl groups and ester linkages in the epoxy network. The recycled samples exhibit improved interfacial bonding, electrical insulation performance, and mechanical properties. At 10 MPa, TEOA increases the breakdown strength by 9.4%, reduces the dielectric loss at 50 Hz by 18.1%, and increases the tensile strength by 7.5%. Relative to the pristine epoxy vitrimer, the 5 wt% TEOA-containing recycled sample processed at 200°C and 10 MPa for 2 h retains 95.6% of the breakdown strength and 96.1% of the tensile strength. These results demonstrate that TEOA-assisted interfacial modification promotes dynamic covalent network reorganization and improves property recovery during epoxy vitrimer recycling.