Effects of Multiwalled Carbon Nanotubes and Graphene Nanoplatelets Filled Hybrid Epoxy Nanocomposites on Electrical and Mechanical Properties

The material properties can be significantly changed, with the addition of low concentration of nanofillers. With the integration of two nanofillers into the epoxy matrix, new hybrid nanocomposites can be obtained to suit requirements of the high voltage applications by improving desired electrical, thermal and mechanical properties. Indeed, hybrid nanocomposites are the fastest growing areas of material research. In the present work, the feasibility of multi-scale hybrid nanocomposite for conductor core applications was discussed. Composite sheets were fabricated with a very low wt.% of Multi-Walled Carbon Nano Tube(MWCNT) with an average size of 6-13nm and Graphene Nanoplatelets (GNP) with a particle size of 15μm were mixed in to commercially available bisphenol-A epoxy resin reinforced with E-Glassfiber. A homogeneous epoxy-nanofiller mixture is obtained using mechanical stirring followed by slow pultrusion technique. The resulting MWCNT/GNP reinforced epoxy resin was used to fabricate hybrid nanocomposite sheets with 70 wt.% unidirectional Glass Fiber(GF) with density of 400 g/m2. The hybrid nanocomposite sections were processed using pultrusion technique. With this former process glass fiber-epoxy (70:30), GF-epoxy/MWCNT (70:28:2) and GF-Epoxy/ MWCNT/GNP (70:27:2:1, 70:26:2:2, 70:25:2:3) weight percent composite sections were obtained. Dielectric properties were studied using LCR meter in the frequency range from 10Hz to 8MHz and mechanical properties were investigated using Universal Testing Machine. The mechanical tests revealed that the addition of MWCNT improves the tensile strength, cross breaking strength and the GNP enhances the tensile elastic modulus of the hybrid composite sheets. Electrical properties such as dielectric constant and impedance were found to be improved with filler addition. Finally, this work seeks to address the need of hybrid nanocomposite core in high voltage applications and need to understand the changes in electrical and mechanical properties with the addition of hybrid nanofillers.