Effect of incorporation of conductive fillers on mechanical properties and thermal conductivity of epoxy resin composite

Applications of polymer-based nanocomposites continue to rise because of their special properties such as lightweight, low cost, and durability. Among the most important applications is the thermal management of high density electronics which requires effective dissipation of internally generated heat. This paper presents our experimental results on the influence of graphene, multi-walled carbon nanotubes (MWCNTs) and chopped carbon fibers on wear resistance, hardness, impact strength and thermal conductivity of epoxy resin composites. We observed that, within the range of the experimental data (epoxy resin + 1, 3, 5 wt% of graphene or 1, 3, 5 wt% MWCNT or 10, 30, 50 wt% carbon fibers), graphene-enhanced wear resistance of the nanocomposites by 75% compared to 50% and 38% obtained for MWCNT and carbon fiber composite, respectively. The impact resistance of graphene nanocomposite rose by 26% (from 7.3 to 9.2 J/m(2)) while that of MWCNT nanocomposite was improved by 14% (from 7.3 to 8.2 J/m(2)). The thermal conductivity increased 3.6-fold for the graphene nanocomposite compared to threefold for MWCNT nanocomposite and a meager 0.63-fold for carbon fiber composite. These enhancements in mechanical and thermal properties are generally linear within the experimental limits. The huge increase in thermal conductivity, especially for the graphene and MWCNT nanocomposites makes the composites readily applicable as high conductive materials for use as heat spreaders and thermal pads.