Effects of Chemical Functionalization of Multi Wall Carbon Nanotubes on the Heat Transport Behaviour of Polypropylene based Nanocomposites

摘要

The influences of chemical modified multiwalled carbon nanotubes (MWNT) on the thermal transport properties of melt blended polypropylene composites have been investigated in function of filler content and temperature. At this purpose, relatively low amounts of carbon nanotubes (≤ 5% by weight) where added in the melt of an injection molding grade polypropylene (PP) resin. Attention was paid on three different commercial MWNTs with the same aspect ratio, one not functionalized and two chemically modified with carboxyl -COOH and amino -NH2 groups, respectively. Preliminary results in terms of thermal conductivity always confirmed a dependence of this parameter from both test temperature and filler content, with effects much more pronounced in presence of amino-functionalized MWNTs with respect to carboxyl-modified ones. In particular, focusing the attention on systems with 1, 3 and 5 wt% of carbon nanotubes examined at 30, 50, 70 and 100 °C, the most marked influence of the filler functionalization on the thermal conductivity of composites was detected in presence of 5% by weight of MWNT-NH2 at 30 °C (~+ 46% with respect to the neat matrix at the same temperature). Further analysis by differential scanning calorimetry (DSC) were also carried out on the same systems.