Effect of Glycerin on Electrical and Thermal properties of PVA/Copper Sulphate Gel polymer electrolytes

Abstract Copper-ion conducting gel polymer electrolyte (GPE) systems based on polymer poly(vinyl alcohol) (PVA) and copper sulphate salt doped with glycerin as plasticizer have been synthesized by using solution casting method. Differential scanning calorimetry is used to examine the thermal effect of glycerin on a plasticized polymer electrolyte (DSC). With the addition of various quantities of glycerin, as a plasticizer in pure PVA and PVA+20wt.%CuSO4 gel polymer electrolyte shows a decrease in the values of melting temperature (54.34°C), glass transition temperature (37.22°C) and percentage of crystallinity (11.65%). Compared to pure PVA, thermal degradation measured from TGA curve for the plasticized gel electrolyte is shifted to lower temperatures and the weight loss of the polymer electrolyte increase with increase of glycerin concentration. From DTG, the temperature of maximum decomposition for PVA is 283.4 oC, and it is decreased with adding 20 wt.% CuSO4 and upon increased concentration of the plasticizer from 1 to 3 mL of glycerin. For pure PVA and PVA+20wt.% CuSO4, ε′ decreases with increasing glycerin concentration and peaks at 3 mL glycerin concentration. The maximum ionic conductivity obtained was 9.39×10-4 S/cm for PVA+20wt.%CuSO4+3 mL glycerin.