Effect of Plasticizer on the Structural and Transport Properties of Mg2+- Ion Conducting Solid Polymer Electrolytes: [PEO: Mg(CH3COO)2]

Abstract

In this study, the use of low molecular weight Ethylene glycol [CH2 (OH).CH2OH] as a new type of plasticizer in polyethylene oxide (PEO)/Mg(CH3COO)2 solid polymer electrolytes preparation was examined. The complexation of Mg(CH3COO)2 salt with the polymer in the presence and absence of plasticizer was confirmed using Fourier transform infrared spectroscopy (FTIR). The Optical Microscopy (OM) results showed that the microstructural evolution of the pristine polymer is as a result of doping and plasticization. The ionic conductivity was measured for the [PEO: Mg(CH3COO)2] systems in the temperature range 296K – 338K using standard four-probe technique. The addition of Ethylene glycol [CH2 (OH).CH2OH] as plasticizer in the solid polymer electrolytes significantly improved the ionic conductivity. No conduction was observed in the solid polymer electrolyte systems without plasticizer except for the 15-wt-% Mg(CH3COO)2-doped system. The temperature dependence of the ionic conductivity reveals the conduction mechanism to be an Arrhenius-type thermally activated process.