Non‐fluorinated PVA / SSA proton exchange membrane studied by positron annihilation technique for fuel cell application

Poly(vinyl alcohol) (PVA) with sulfosuccinic acid (SSA) membrane was prepared with different concentrations of SSA (wt.%) and thermally crosslinked successfully at 100 °C. Ion exchange capacity and proton conductivity were found to increase with increasing the SSA content in the meantime the water uptake and hydration number were declined with the rise in the degree of sulfonation. This anomalous behavior was discussed based on Nerst equation parameters which confirm the results discussion with enhancement with data of contact angle. Tensile strength results suggest the deterioration of the PVA/SSA membranes with increasing SSA content because of the chemical reaction of SSA and PVA chains. Positron annihilation results were found to enhance the electrochemical‐mechanical results of the membranes. The o‐Ps lifetime was found to increase with increasing degree of sulfonation while SO 3 was working as an inhibitor agent of PS formation as o‐Ps Intensity was declined with an elevated percentage of SSA content. The o‐Ps lifetime as a function of temperature for different PVA/SSA membranes having different SSA content increased with increasing SSA content. Furthermore, the glass transition temperature of PVA/SSA membranes was found to decrease with increasing the SSA content. The results were discussed based on the free volume theory.