Solid polymer electrolyte films (SPEs) based on poly(methyl methacrylate) are prepared using a solution cast technique. The temperature-dependent behavior of dielectric, modulus spectra and ac conductivity has been investigated. The long tail of the real part of modulus (M 0 ) in the low frequency indicates the capacitive nature of the samples. The frequency dependence of imaginary part of modulus (M 00 ) shows a non-Debye relaxation that has been explained using the Kohlrausch-Williams-Watts stretched exponential function. The activation energy for the relaxation is almost same as the activation energy for the conduction. The relaxation time obtained from the tangent loss graph (τ δ ) is about two orders of magnitude larger than that obtained from the imaginary part of modulus graph (τ m ). The ac conductivity has been found to obey Jonscher's universal power law. Transport parameters show that addition of filler creates additional hopping sites for the charge carriers and also increases the charge carrier density. It is also observed that the higher ionic conductivity at higher temperature is due to increased thermally activated hopping rates accompanied by a significant increase in carrier concentration. The contribution of carrier concentration to the total conductivity is also confirmed from Summerfield scaling. POLYM. ENG. SCI., 60:297-305, 2020.

The polymer nanocomposite films (PNC) with varying amounts of organically modified sodium montmorillonite (DMMT) clay in poly(methyl methacrylate) (PMMA) based polymer matrix were prepared by solution cast technique. Dielectric measurements were carried out on these films as a function of frequency at 30°C and 100°C. The addition of clay significantly improved the ionic conductivity. Transport parameters, such as the diffusion coefficient (D), number density (n) and mobility (μ) of charge carriers were determined using a new approach, which is based on impedance spectroscopy. The temperature‐dependent dc conductivity, relaxation and mobility plots obey the Arrhenius rule. The results suggest that the higher ionic conductivity of these PNC films at elevated temperature is not only due to increased mobility of ions, but it is accompanied by a significant increase in carrier concentration. Analysis of DSC thermogram reveals a very high percentage of amorphous content for all samples. A good correlation among dielectric permittivity, carrier concentration, mobility and ionic conductivity has also been observed. POLYM. ENG. SCI., 58:220–227, 2018. © 2017 Society of Plastics Engineers

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