Silicon-Bridged Epoxy Vitrimers with Antibacterial and UV-Blocking Properties

The development of multifunctional epoxy resins that can be degradable and reprocessed is of great significance for the conservation of non-renewable resources and environmental protection. Herein, curing agents based on nitrogen–silicone Schiff base (BOB) and silica-bridged epoxy resin (ETOD) were designed and successfully synthesized. Then, ETOD was cured using BOB to fabricate a multi-silicon-bridge epoxy vitrimer containing dynamic imine bonds (BOB/ETOD). Notably, because of the presence of a large number of siloxane chain segments, BOB/ETOD exhibited excellent flame retardancy (the peak heat release rate (pHRR) was 57.7% lower than that of conventional epoxy resin (DDM/EP) and a carbon residual rate (RC700) of 27.7%, which is 1.6 times higher than that of DDM/EP). Furthermore, the networks of BOB/ETOD could topologically rearrange due to the reversible exchange reaction of imine bonds, making them degradable and reprocessable. Surprisingly, BOB/ETOD also had excellent antimicrobial (the antimicrobial rate was up to 93%) and UV-blocking properties. This work provides a simple and effective solution for the development of multifunctional epoxy-based vitrimers, which is conducive to further expanding the application field of epoxy resins.