Electrically conductive and super-tough polypropylene/carbon nanotube nanocomposites prepared by melt compounding

Polyethylene–octene copolymer (POE), maleic anhydride-grafted POE (POE-g-MA) and ultrahigh molecular weight polyethylene (UHMWPE) were incorporated as second polymer components with polypropylene/carbon nanotube (PP/CNT) components by melt compounding and their influences on electrical conductivity and toughness of the nanocomposites were studied. POE-containing nanocomposites exhibit not only high electrical conductivity but also super-toughness, which are not considerably dependent on compounding sequences. Though UHMWPE does not largely affect the electrical conductivity of PP/CNT nanocomposites due to its impermeable feature, its toughening efficiency on PP/CNT nanocomposites is rather low. Irrespective of the compounding sequences, the incorporation of POE-g-MA adversely affects the formation of conducting network of CNTs due to its attraction with CNTs, leading to an insulating PP/CNT nanocomposite even with 30 wt% of POE-g-MA. Among the three second polymer components, POE is much preferred in actual applications as it makes PP/CNT nanocomposites super-tough while the conducting feature of the nanocomposites is retained.