Abstract
In this study, we focused on the behavior of the direct-current (dc) conductivity/resistivity in a cryogenically low temperature region (10-300 K) for ethylene vinyl acetate copolymer, acrylonitrile butadiene copolymer, and their 50/50 blend composites filled with different conductive carbons. The composites were prepared through a melt-mixing technique. Different behaviors of the dc resistivity/relative resistivity for the composites were observed; these behaviors depended on the nature of the polymers, the filler types, and the filler concentration when plotted with respect to the temperature. The results of dc conductivity were fitted with some existing theoretical models, including Arrhenius, Kivelson, and Mott's variable range hopping, to check their applicability for these composite systems. We observed that none of the models was applicable within the entire range of measurement temperatures but were confined within limited temperature ranges. The reason behind the nonapplicability of the models is discussed with consideration of their drawbacks and limitations. (c) 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43541.