Effect of the Sulfonation on Proton Exchange Membrane Synthesized from Polyvinyl Alcohol for Fuel Cell

摘要

Proton exchange membranes were synthesized from the Polyvinyl Alcohol copolymer (PVA) crosslinked with potassium hydroxide (KOH) and formaldehyde (CH_2O), and sulfonated in 1, 2 and 3 hours of reaction to evaluate their application in fuel cells. The physicochemical and mechanical properties of the membranes were characterized. The results show that the membrane sulfonated at 3 hours presented the highest ion exchange capacity (1.19 meq/g) and a very good water retention (240%), due to the hydrophilic character of the sulfonic groups added to the polymer matrix, while the mechanical properties decline with respect the unmodified membrane and the FTIR tests confirmed the presence of the sulfonic groups (-SO_3H) in the polymer. These results demonstrate acceptable characteristics of the prepared membranes to be used in fuel cells.