Enhancing the Electrical Properties of Polystyrene – Multiwalled Carbon Nanotubes Composites by the Introduction of Magnesium Oxide to the Composite Matrix by Melt Mixing

This research aimed to test the effect of metal oxides on the electrical conductivity of polymer|CNT composites. Polymer|CNT composites often have a percolation threshold, which is the highest electrical conductivity that the polymer could reach by the addition of CNT to it. Once the percolation threshold is reached, the electrical conductivity barely changes with the addition of CNT. This research tested whether adding MgO to PS|MWCNT composites would influence the electrical conductivity of it, as oxygen has a positive effect on the electrical conductivity of CNT. This was done by fixing the percentage of MWCNT at 1 wt. % and adding MgO at various percentages. For reference, MgO was also added to PS without MWCNT to test whether MgO alone has an influence on the electrical conductivity. The research has found that adding MgO alone to PS had no effect on the electrical conductivity of it and it remained an insulator of electricity at electrical conductivities around 7E-9. However, with the presence of 1 wt. % of MWCNT, the addition of MgO did influence the electrical conductivity, as it was increased by several orders of magnitudes despite the fixed percentage of MWCNT. By adding 4% MgO, the electrical conductivity of polystyrene ‐1 wt. % MWCNT was increased from 6.4E-6 to 1.3E-3.