Facile Synthesis of Novel Polyethyleneimine Functionalized Polymeric Protic Ionic Liquids (PolyE‐ILs) with Protagonist Properties for Acid Catalysis

Polyethyleneimine (PEI), a potent architecture backbone was explored for the synthesis of novel polymeric ionic liquids (PolyE‐ILs) with protagonist properties. The simple quaternization of PEI dendrimer with Bronsted acids (H2SO4, H3PO4, CH3SO3H, CF3COOH and TsOH) leads to formation of series of protic PolyE‐ILs with corresponding counter anions [HSO4]−, [H2PO4]−, [CH3SO3]−, [CF3COO]− and [TsO]−. The physicochemical properties of synthesized PolyE‐ILs were studied by using TGA, Hammett acidity, hydrodynamic radii, solubility, and elemental analysis. PolyE‐ILs showed characteristic Hammett acidity (0.94–1.78), good thermal stability (