Influence of Diallyl Disulfide on the Properties of Biobased Antimicrobial Vitrimers for Microimprint Lithography

This work contributes to the development of sustainable materials by creating biobased photopolymerized vitrimers with antimicrobial, shape-memory, and self-welding capabilities, essential for industries using light-based manufacturing technologies where petroleum-based materials lacking such properties are currently used. In this study, the influence of the amount of diallyl disulfide, which has antimicrobial properties and forms dynamic bonds, on the vitrimeric behavior and antimicrobial activity of biobased vitrimers synthesized from acrylated epoxidized soybean oil, 2-hydroxy-3-phenoxypropyl acrylate, and diallyl disulfide was determined. The addition of 0.35 mol of diallyl disulfide to a resin containing 1 mol of acrylated epoxidized soybean oil and 1 mol of 2-hydroxy-3-phenoxypropyl acrylate was found to reduce resin viscosity by 55%, photocuring rate by 30% and shrinkage to 0%, and increase polymer flexibility by 53%. These polymers exhibited excellent self-welding and shape-memory properties enabled by dynamic disulfide bond exchange. Antimicrobial tests have shown that resins containing more than 0.05 mol of diallyl disulfide, 1 mol of acrylated epoxidized soybean oil, and 1 mol of 2-hydroxy-3-phenoxypropyl acrylate inhibit the bacterial growth of Escherichia coli by more than 97%, Staphylococcus aureus by more than 49%, as well as the fungal growth of Aspergillus flavus by more than 83%, and Aspergillus niger by more than 38% after 1 h of direct contact with the bacterial or fungal suspensions. Micrometer-scale patterns formed using microimprint lithography confirmed the potential of these vitrimers with diallyl disulfide moieties as antimicrobial advanced engineering materials for applications where flexibility and sustainability are required.