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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 (RC 700 ) 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.

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As an important thermosetting material, flame-retardant epoxy resin has various applications in the aerospace, chemical, and electronics industry, and other fields. However, the flame retardancy of epoxy resins is often improved at the expense of mechanical performance. The contradiction between flame retardancy and mechanical properties seriously impedes the practical applications of epoxy resin (EP). Herein, iron-loaded polydopamine functionalized montmorillonite (D-Mt-Fe3+), which was prepared by dopamine, iron chloride and montmorillonite in an aqueous solution, was introduced to prepare iron-loaded polydopamine functionalized montmorillonite/epoxy resin composites (D-Mt-Fe3+/EP). As expected, D-Mt-Fe3+/EP-10 with 10 phr of D-Mt-Fe3+ passed the UL-94 V-0 rating, achieved a limiting oxygen index (LOI) value of 31.0% and reduced the smoke production rate (SPR) and total smoke production (TSP), indicating that the introduction of D-Mt-Fe3+ could endow EP with satisfactory flame retardancy through the radical scavenging function of dopamine in the gas phase and the catalytic charring effect of iron ions, respectively. Encouragingly, the mechanical property was also enhanced with the flexural strength increased by 25.5%. This work provided an attractive strategy for improving both the mechanical properties and fire resistance of EP, which greatly broadened their applications in the chemical industry and electronics field, etc.