PHASE-BEHAVIOR OF COMPLEXES OF PVA AND ACID SALTS

Polymer electrolytes of COLBON(R)(BASF(TM)) (based on poly vinyl alcoh ol (PVA)) complexed with KHSO4 of different stoichiometric ratios have been characterized using high-resolution:ac calorimetry, differential scanning calorimetry (DSC) and electrical conductivity measurements. These complexes have been prepared by solvent casting method using H3P O2 as solvent. All complexes have been confirmed to be amorphous up to 450 K by thermal and conductivity measurements. The glass transition temperature is maintained low (around T-g approximate to 213 K), witho ut largely depressing conductivity up to the KHSO4 weight fraction x = 0.5. The electrolyte with x = 0.09 exhibits the highest conductivity, of 1.1 x 10(-2) (Omega cm)(-1) at room temperature. The activation en ergy of charge transport is independent of salt concentration (x < 0.5 ) and remains mainly constant at 0.23 eV in the 300-360 K temperature range. (C) 1998 Published by Elsevier Science Ltd. All rights reserved .