Construction of Multifunctional Polyionic Liquids for Efficient Chemical Fixation of CO₂

The cycloaddition of carbon dioxide (CO2) with epoxides affords cyclic carbonates, which is a reaction celebrated for its environmental benignity and high efficiency, achieving 100% atomic economy. This process is widely recognized as one of the most promising strategies for CO2 conversion. In this study, a poly(ionic liquid) bearing trifluoromethyl and amino groups was developed. The trifluoromethyl/amino-functionalized ionic polymer catalyst was synthesized via a one-pot reaction using 2,2,2-trifluoroethyl methacrylate (FMA), an amino-containing imidazolium ionic liquid ([NEt2VIm][Br–]·HBr), and ethylene glycol dimethacrylate (EGDMA) as monomers. The acquired materials with different monomer ratios were named FMA-P[NEt2VIm]-PEGDMA-1 (1F1N3E), FMA-P[NEt2VIm]-PEGDMA-2 (1F1N2E), FMA-P[NEt2VIm]-PEGDMA-3 (1F2N1E), and FMA-P[NEt2VIm]-PEGDMA-4 (1F3N1E). The exact structures of the resulting materials were fully characterized by FT-IR, SEM, 13C NMR, TGA, XPS, and so on to verify the formation of the target architecture. The catalyst incorporates multiple catalytically active sites, including amino groups, imidazolium moieties, fluorine atoms, and bromide ions, enabling efficient facilitation of the CO2-epoxide cycloaddition under solvent-free conditions without the need for cocatalysts. This approach provides a viable pathway for sustainable CO2 utilization.