Predicting the thermal conductivity of polypropylene-multiwall carbon nanotubes using the Krenchel model

Abstract

AbstractThe thermal conductivity of particulate composite models is well documented in the literature. This paper attempts to fit the experimental data for the thermal conductivity of polymer nanocomposites to a three-phase Krenchel model. The use of this model is applicable for structures that consist of a polymer matrix, a nanofiller, and an interfacial layer around the nanoparticles. The effect of Kapitza’s thermal resistance is implemented in the model along with the assumption that the nanofillers are cylindrical and well connected to each other; however, no parameters related to any type of dispersants or the dispersion techniques are stated in the model. The results of the three-phase Krenchel model were validated using the experimental data of thermal conductivity of multiwall carbon nanotubes embedded in polypropylene matrix nanocomposites. It was found that the model was in good agreement with the experimental thermal conductivity data. Moreover, the results from the model showed that the filler geometrical packing factor was 0.75; consequently, the carbon nanotubes formed bundles of several cylindrical tubes. The length of the interface between the nanotubes and the polymer matrix was around 1 Å. Finally, the thermal conductivity of the composite bundle cylinder was 21.63 W/(m K).