(332i) In-Situ Ionization of Telechelic Oligomers into Ionic Supramolecular Block Polymers

The reprocessability and recyclability of conventional polymers are severely constrained by the high covalent C-C bond energy (ca. 150 k_BT), rendering the depolymerization process energetically unfavorable. Ionic interactions emerge as a compelling alternative, providing non-covalent forces that link oligomer building blocks with bond energies up to 100 k_BT. These energies can be finely tuned through the material's permittivity and external stimuli. However, the presence of counterions can interfere with chain association, leading to a substantial reduction in effective bond energy. In this study, we introduce a novel, environmentally friendly synthetic strategy for creating counter-ion free supramolecular block polymers without relying on solvent-intensive purification steps (e.g., dialysis). This is achieved by employing charge-neutral telechelic oligomers with nucleophilic (e.g., imidazole) and alkylating (e.g., alkyl sulfonate) end groups, facilitating in-situ ionization and coupling to yield form supramolecular block polymers (ISBPs) with aprotic ionic liquid-like junctions. We will elucidate the ion pair binding constant, the effective degree of polymerization, and the self-assembled structures in both solution and bulk states.

The acquired insights will provide a foundation for the development of ion-containing associating polymers that can be reprocessed and recycled and are thus sustainable alternatives to conventional commodity plastics, e.g., ionic polyolefins that can be assembled and disassembled on demand.