Responsive Gels Based on a Dynamic Covalent Trithiocarbonate Cross-Linker

Dimethacrylate trithiocarbonate was synthesized and used as a dynamic covalent cross-linker to prepare PMMA and PSt gels via radical polymerization. The swelling properties of the PMMA gels were studied and showed that in the presence of radicals the gels reorganize to accommodate forces generated by the swelling processes. This reshuffling of the cross-link network yields an increase in the swelling ratio (up to 300% increase) of the PMMA gels. Two different radical generators, a thermal initiator and a CuI/L complex, were successfully used to trigger the reorganization of the gels. To illustrate the broad utility of the procedure, three discrete pieces of gels were fused into one single piece to demonstrate that dynamic covalent cross-linkers can be used to prepare materials that can be reprocessed and/or undergo self-repair.