Electrical, thermal and thermo-mechanical properties of epoxy/multi-wall carbon nanotubes/mineral fillers nanocomposites

Epoxy/multi-wall carbon nanotubes and epoxy/multi-wall carbon nanotubes/mineral fillers nanocomposites were produced via in situ polymerization assisted by three-roll-milling. Epoxy/multi-wall carbon nanotubes nanocomposites presented very low electrical percolation threshold, near to 0.05 wt %. In this study, we used different mineral fillers, with different aspect ratios: calcium carbonate, montmorillonite, and sepiolite. We evaluated the effect of the addition of these fillers on electrical, thermal, and thermo-mechanical properties of epoxy/multi-wall carbon nanotubes nanocomposites. The addition of calcium carbonate in epoxy/multi-wall carbon nanotubes nanocomposites increased the electrical conductivity of this nanocomposite, due to volume exclusion effect. The addition of sepiolite decreased the loss factor and improved electrical constant, however, reduced the electrical conductivity in these nanocomposites, when compared to epoxy/multi-wall carbon nanotubes. Regarding thermal properties, no significant change in glass transition was observed. Thermo-mechanical analysis for nanocomposites showed slight changes in tan (δ) and storage modulus, which is related to the interaction between epoxy, multi-wall carbon nanotubes and mineral fillers.