Nonlinear Conductivity of Polymer Nanocomposites: A Study on Epoxy Resin\/Silicon Carbide Materials

The nonlinear conductivity of polymer composites is helpful in regulating electric field distribution and dissipating surface charge and/or space charge. In this article, silicon carbide (SiC) nanoparticles are used as the nonlinear filler and added to epoxy resin. The filler loadings were 0, 1, 3, 7, and 10 wt%. The glass transition temperature, dielectric spectroscopy, and nonlinear conductivity are investigated. The results show that the glass transition temperature and the real part of the complex permittivity are closely related to the interaction zone surrounding the nanoparticles. The epoxy/SiC nanocomposites present distinct nonlinear conduction characteristics. By considering the effect of the interaction zone around the nanoparticles, a theoretical model is used to qualitatively explain the field dependence and temperature dependence of the nonlinear conductivity.