IONIC-CONDUCTION IN PLASTICIZED PVC PMMA BLEND POLYMER ELECTROLYTES/

The new plasticized polymer electrolyte composed of the blend of poly( vinyl chloride) (PVC) and poly(methyl methacrylate) (PMMA) as a host p olymer, the mixture of ethylene carbonate and propylene carbonate as a plasticizer, and LiCF3SO3 as a salt was studied. The effect of the PM MA/PVC blend ratio and the plasticizer content on the ionic conduction s in these electrolytes were investigated. The electrolyte films revea led a phase separated morphology due to immiscibility of the PVC with the plasticizer; the PVC-rich phase and the plasticizer-rich phase wer e produced during the film casting. The mechanical property was signif icantly enhanced by the incorporation of PVC into the electrolyte syst em. The ionic conductivity decreased with increasing the PVC/PMMA rati o and increased with increasing the plasticizer content. These behavio rs were explained in terms of the morphology of the film. Since the pl asticizer-rich phase contains much more plasticizer than the PVC-rich phase, the ions preferentially move through plasticizer-rich phase. Du e to the slow ionic transport through the PVC-rich phase, the conducti vity decreased with increasing PVC/PMMA ratio. (C) 1997 Elsevier Scien ce Ltd.