Dielectric properties of polyethylene with graphene-like additive: Effect of the fabrication technique

The purposes of this work are to investigate the electrical percolation threshold of a low-density polyethylene (LDPE) nanocomposite filled with a new graphene-like (G) additive and to study the effect of the fabrication process on this property. For this reason, two different fabrication techniques were utilized: micro-extrusion and high-energy ball milling. The composites electrical properties were evaluated with broadband dielectric spectroscopy both in low- and high-voltages (LV and HV) configurations. Finally, the effect of maleic anhydride utilized as compatibilizer in order to reduce the percolation threshold was evaluated. It was found that, at low voltages, the percolation threshold for the micro-extruded composite was at the 25% in weight (wt%) of G, while, for the high-energy ball milled it was at 20wt%. It was also observed that the conductivity of both the composites was strongly affected by the applied voltage. Furthermore, the utilization of maleic anhydride was found to be not effective in lowering the nanocomposite percolation threshold.