Morphology and carbon dioxide transport properties of polyurethane blend membranes

The polyurethane (PU) based blend membranes were prepared by the solvent evaporation process. A polyetherimide (PEI) and a poly(amide-imide) (PAI) have been chosen as a blend component. The CO2 separation properties of PU based blend membranes as a function of different blend ratios have been studied. The morphologies of PU-based blend membranes were investigated by SEM. The resulting membranes were immiscible system and phase separation occurred as decreasing amount of PU. The permeabilities were decreased as the blend ratio increased. The CO2/N2 selectivity of PU-based blend membranes was improved with decreasing the amount of PU. The CO2 separation properties of PU-based blend membranes depended on the volume fraction of the dispersion component.