PEG-imidazolium-functionalized 6FDA-durene polyimide as a novel polymeric membrane for enhanced CO<sub>2</sub> separation

Abstract

A series of poly(ethylene glycol)-imidazolium-functionalized 6FDA-durene polyimides (PEG-Im-PIs) with a range of PEG chain lengths was developed. The structures and properties of this series, as well as the gas separation properties of the corresponding polymer membranes, were studied. A PEG group and an imidazolium-based ionic group, both of which acted as CO2-solubilizing groups, were incorporated onto a rigid polyimide backbone to yield a very high CO2 solubility and, hence, excellent CO2/CH4 (49.2) and CO2/N-2 (40.1) permselectivities while maintaining a good permeability of polyimide.