Investigation of the thermal conductivity enhancement mechanism of polymer composites with carbon-based fillers by scanning thermal microscopy

In order to elucidate the mechanism of enhancement heat transfer in polymer composites, this work, we investigated two types polymer-carbon filler composites. This investigation was made using scanning thermal microscopy (SThM) with Wollaston microprobe operated active mode as a function carbon weight fraction within matrix. Samples consist high-density polyethylene (HDPE) filled 50 µm expanded graphite (EG) and polyvinylidene difluoride (PVDF) containing multiwall nanotubes (MWCNTs). For HDPE/EG samples, SThM images allow detection zones conductance larger than that matrix for highest studied concentration. These correspond EG agglomerations explain observed conductivity k composite. PVDF/MWCNTs it is found increases from 0.25 W m −1 K pristine PVDF 0.37 nanocomposites 8 wt. % MWCNTs. variation vs concentration good correspondence β phase relative percentage nanocomposites. suggests rather due formation resulting addition MWCNTs itself. Thus, tuning thermophysical properties polymer-based can establish new design laws confer them specific properties.