LAUSR

Abstract The thermal conductivity (TC) of polymer composites with randomly distributed hybrid fillers is investigated numerically and theoretically. The effective thermal conductivity (ETC) of such composites is examined under various effects, such as the TC ratios, volume fraction (VF), and particle distribution, particle size, and particularly thermal contact resistance (TCR). The contribution of particle distribution to the ETC were explained comprehensively, which is as a function of projected area and effective length of hybrid fillers. Results indicated that the optimal ETC was affected significantly by particle distribution and particle size at high VF, high TC, low TCR, and largely total particle size of hybrid fillers. However, particle distribution and particle size show not to affect considerably to the value of the optimal TC ratio between two fillers. Particularly, it was confirmed that the TC is generally enhanced when more particles are stacked and concentrated along the thermal flow direction regardless of the effects of TCR. In addition, modified Hashin-Shtrikman model by Ngo's study again shows a good TC prediction even with the TCR effect. These results are very good in practical optimization process to achieve the maximum ETC of composites, thus total cost of composite synthesis can be reduced significantly.