Acid–Base Membranes for Solid Polymer Fuel Cells

Acid–base membranes have been prepared by mixing a 1-vinyl-1,2,4-triazole polymer (PVT) with phenol-2,4-disulfonic acid (PDSA) in the presence of products of intermolecular crosslinking of polyvinyl alcohol and oxalic acid. The composition and structure of the membranes have been studied by elemental analysis and IR and NMR spectroscopy techniques. The membranes are thermally stable up to 245°C. Their electrical conductivity increases from 6.23 mS cm−1 (PVT–PDSA 80 : 20 wt % membrane) to 59.8 mS cm−1 (PVT–PDSA 10 : 90 wt %) with increasing temperature and phenol-2,4-disulfonic acid content at a temperature of 80°C and a humidity of 75%. The activation energy of the membranes ranges from 19.5 to 38.2 kJ/mol, respectively. The water uptake of membranes, which determines, among other things, the electrical conductivity, depends on the PVT content: the water uptake decreases from 200 to 50% with an increase in its amount in the membrane composition from 9.1 to 81.30 mol %, leading to a decrease in electrical conductivity along with a decrease in the proportion of PDSA.