| description abstract | Acid–base blends of sulfonated polyethersulfone (SPES) with pristine and aminated polyetherimide (APEI) are synthesized. Three blends polyethersulfone (PES)/polyetherimide (PEI), SPES/PEI, and SPES/APEI are prepared and characterized to evaluate their structural, morphological, mechanical, and other properties. Ion exchange capacity (IEC) of SPES/APEI and SPES/PEI blend membranes was determined to be 3.0 and 2.7 meq g−1, which is a substantial improvement over the 1.0 meq g−1 exhibited by unmodified PES/PEI blend. The proton conductivity of 0.093 S cm−1 displayed by SPES/APEI blend is found to be comparable to that of commercial Nafion membrane (0.056 S cm−1) and far superior to conductivities of 0.091 and 0.082 S cm−1 shown by SPES/PEI and PES/PEI blends, respectively. Further, water sorption observed in case of SPES/APEI and SPES/PEI blends was in the range 17–18% over a soaking time period of 12 hrs, which is ideal for proton conduction accompanied by lowmembrane swelling. The methanol permeabilities of SPES/APEI and SPES/PEI blends are found to be 2.5 أ— 10−7 and 3.47 أ— 10−7 cm2 s−1, respectively. Compared to unmodified PES/PEI blend which revealed a methanol sorption of 12.3%, the modified blends SPES/PEI (9.6%) and SPES/APEI (7.5%) exhibited much lower methanol uptake over a sorption time of 12 hrs, indicating their capacity for low fuel bypass. The results demonstrate the promising potential of polymer blends made by combining a sulfonated polymer with an aminated polymer, such as SPES/APEI for fuel cell (FC) applications. | |
