Dc and Ac conductivity of polyaniline/poly (methyl methacrylathe) blends below the percolation threshold

In this work we present results of thermal spectral and conductivity studies on polyaniline/poly (methylmethacrylate) composite films with polyaniline Wt% situated under the percolation threshold. The glass transition temperature Tg is significantly modified by the presence of polyaniline. For polyaniline Wt% not exceeding 0.3%, the Tg decreases, but for specimens having highest amounts it increases. The Uv–Visible absorption spectroscopy indicates the presence of characteristic absorption bands of polyaniline. When the amount of polyaniline is increased from 0% to 0.5%, the dc conductivity shows an increase with a maximum attained at about 0.1% followed by a decrease. A correlation with the variation of Tg in this domain of polyaniline concentration is proposed.

► Polyaniline/PMMA films with a polyaniline amount less than the percolation threshold.
► The Dc conductivity is due to ionic motion.
► The Ac conductivity is well described by the universal law of Jonscher.
► A power law is observed in the high frequency range.
► The exponent depends on temperature and presents values which can exceed unity.