Electrical and mechanical properties of graphene/carbon nanotube hybrid nanocomposites

Polymer nanocomposites with improved electrical and mechanical properties can be formulated by proper dispersion of conductive high aspect ratio nanofiller within the host polymer matrix. In this work, the microstructure, processing behavior, electrical and mechanical properties of melt-mixed graphene nanoplatelets (GNP)/polypropylene (PP) nanocomposites were investigated. In addition, the influence of processing conditions on the electrical properties of GNP/PP nanocomposites was evaluated. Moreover, GNP: carbon nanotube (CNT)/PP hybrids were prepared aiming at formulating nanostructured material with synergistic properties. The electrical percolation threshold of GNP/PP nanocomposite was found to be similar to 4 vol%. However, upon the introduction of only 1 wt% (0.52 vol%) CNT, significant improvement in the electrical properties was obtained. The CNT was found to bridge the distance between the GNP particles. At constant overall nanofiller concentration, GNP:CNT/PP hybrids exhibited improved properties with the increase in CNT volume fraction due to the better dispersion of nanotubes and strong adhesion at the nanotube/PP interface. (c) 2015 Elsevier B.V. All rights reserved.