The characteristics of high temperature polymer electrolyte membranes for fuel cell based on 2-pyridene based polybenzimidazole blended with poly(vinyl-phosphonic acid)

The present study has focused on exploring new 2-pyridine-bridge-based polybenzimidazole (2-Py-PBIs) based materials for various energy-related uses in proton exchange membrane fuel cells (PEMFC). An electrochemical device, which transforms chemical energy into electrical energy, is known as fuel cell. Using solution polymerization with polyphosphoric acid as a solvent, a series of 2-Py-PBIs were synthesised from the 4,4'-([2,4′-bipyridine]-2′,6′-diyl)bis (benzene-1,2-diamine). 2-Pyridine bridge Polybenzimidazoles are cross-linked with poly (vinylphosphonic acid), which helps us to improve membrane properties like mechanical properties and proton conductivities. FT-IR was used to characterize chemical structure, Ubbelohde viscometer was employed to determine the inherent viscosity. Additionally investigated were the oxidative stability, swelling ratio, ion exchange capability, and water uptake for 2-Py-PBIs. Thermogravimetric analysis is used to evaluate thermal stability. The obtained 2-Py-PBIs membranes were thermally stable and mechanically strong when compared with conventional polybenzimidazole-based membranes. The 2-Py-PBIs:PVPA membranes showed proton conductivity between 0.10 µS/m to 4.65 µS/m.