The role of conductive pathways in the conductivity and rheological behavior of poly(methyl methacrylate)-graphite composites

Up to now, research on the dynamic process of conductive network formation has tended to focus on composite particles with one-dimensional geometry, such as carbon black and carbon nanotubes. However, studies on this subject based on fillers with two-dimensional structure, such as graphite, are rare in the literature. In this work, the dynamic percolation and rheological properties of poly(methyl methacrylate) (PMMA)–graphite composites under an electric field were investigated. The activation energies of conductive network formation and polymer matrix mobility were calculated from the temperature dependence of the percolation time and the zero-shear viscosity. It was found that the activation energy calculated from the zero-shear viscosity was not influenced by the electric field in the concentration range investigated, but the electric field had an effect on the activation energy calculated from the percolation time. This finding emphasizes that the electrical and rheological properties have different physical origins. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43810.