Siloxane-Based Main-Chain Poly(ionic liquid)s via a Debus-Radziszewski Reaction

Herein, we synthesized a series of siloxane-based poly(ionic liquid)s (PILs) with imidazolium-type species in the main chain via the multicomponent Debus-Radziszewski reaction. We employed oligodimethylsiloxane diamine precursors to integrate flexible spacers in the polymer backbone and ultimately succeeded in obtaining main-chain PILs with low glass transition temperatures (T _g s) in the range of -40 to -18 °C. Such PILs were combined with conventional hydrophobic vinylimidazolium-based PILs for the fabrication of porous membranes via interpolyelectrolyte complexation with poly(acrylic acid), which leads to enhanced mechanical performance in the tensile testing measurements. This study will enrich the structure library of main-chain PILs and open up more opportunities for potential industrial applications of porous imidazolium-based membranes.