Miscibility and Conductivities of PEO/PMMA-LiClO₄ Solid Polymer Electrolyte

Abstract:

Thin films of poly (ethylene oxide) (PEO), poly (methyl methacrylate) (PMMA) and selected blends of PEO/PMMA with and without the addition of LiClO₄ were prepared using solution casting technique. The presence of a single T_g which corresponds closely to that of the Gordon Taylor equation confirms the miscibility of both the salt-free and salt-doped blends. The T_gs and the ion conductivity (σ) at room temperature of PEO, PMMA and the PEO/PMMA blends generally increase with ascending salt concentration (Y). Variations in the σ value as a function of Y for all the three systems correlate closely with their respective T_g results. PMMA-salt complex records the lowest σ value at all salt concentrations. PEO/PMMA/LiClO₄ blend with 75 wt% PEO exhibits the highest σ value of 5 x 10^-7 S cm^-1 at Y = 0.10. The σ value of the blend-salt system is observed to be slightly lower than that of the PEO-salt system. This is due to reduced segmental motion cause by increased T_g of the blend and a decrease in free ions in the amorphous phase of PEO as a small amount of the salt is solvated by PMMA in the blend. Therefore, the percolation path lies in the amorphous PEO rich phase of the blend.

• Periodical: Advanced Materials Research (Volume 812)
• Pages: 267-270
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.812.267
• Online since: September 2013
• Authors: Siti Rozana Abd Karim, Lai Har Sim, Chin Han Chan, Nurul Fatahah Asyqin Zainal, Masitah Abu Kassim
• Keywords: Glass Transition Temperature, Ion Conductivity, Miscibility, Polymer Blend, Solid Polymer Electrolyte

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