Antimonic acid and sulfonated polystyrene proton-conducting polymeric composites

Polymer composites formed of a proton conductor and polyvinylidene fluoride (PVDF) are prepared. Sulfonated polystyrene (SPS) and antimonic acid (AAc) are used as organic and inorganic proton conductor, respectively. PVDF is the insulating matrix used as a binder to improve the mechanical stability of the composites compared with the pure proton conductors. The effect of t he SPS and/or AAc on both the glass transition temperature, T-g, and the me lting temperature, T-m, of the PVDF is studied. The ionic conductivity of t he composites, after water vapor exposure at r.t., and after water immersio n at 50 degrees C, is measured at room temperature. The overall conductivit y of the composite increases with time up to saturation, which is attained: (i) after 17 h for the water vapor exposure experiment and (ii) after appr oximate to 10 min, for the water immersion experiment. The ionic conductivi ty of the composites is smaller than that of the pure protonic conductors, but the composites show high-dimensional stability. The shape of the conduc tivity curve depends on the proton conductor chosen. (C) 2000 Elsevier Scie nce B.V. All rights reserved.