Seawater-Degradable and Antibacterial Epoxy Thermosets Employing Betaine Ester Linkages

Poor degradation and microbial contamination are two major challenges associated with the application of thermoset resins in marine settings. Here, the synthesis of betaine ester-functionalized epoxy resins with tunable degradation and antibacterial activity in seawater-like environments is presented. Chloroacetate-decorated epoxy resins were first synthesized using a ring-opening reaction and subsequently reacted with tertiary amine-based curing agents. The resulting betaine ester-decorated epoxy thermosets featured a yield strength exceeding 80 MPa and tunable degradation capability. Rapid degradation was realized under mild alkali conditions, corresponding approximately to weakly alkaline seawater conditions. Integration of cetyl chloroacetate further increased the betaine ester content and bactericidal performance. A bactericide rate of 99.34% against Staphylococcus aureus of MF10-CCA1PMD was achieved, which compares favorably to that of established antibacterial agents. The results demonstrate an effective route for realizing functionalized epoxy resins that could advance the development of thermosetting materials with enhanced functionality and reduced environmental cost for marine environments.