Keywords: , , , , , , , , , , , , , , , , , ,

Abstract: Nanocomposite phase change materials (PCMs) were prepared by adding silver nanoparticles to isotactic polypropylene (iPP) and an iPP/paraffin wax phase change materials. The Ag nanoparticles were found to be well dispersed in both iPP and the iPP/wax composite, and filler agglomeration was found to increase with increasing filler content. The nanoparticles did not significantly affect the modulus of the iPP on its own, but when Ag and paraffin wax were both added to the iPP PCM, the modulus was improved. The thermal and electrical conductivities of these materials were also investigated. It was found that the most significant enhancement in these two properties occurred in the iPP/wax/Ag nanocomposites. The thermal conductivities of these nanocomposites increased with filler content to a point and then levelled off, while the electrical conductivity was found to increase continuously with filler content. The effect of the cooling rate of the PCMs on the thermal conductivity was also investigated and it was determined that the samples that had been cooled slowly were more thermally conductive than those which had been quenched.

Reference: Master’s Thesis, University of the Free State (QwaQwa Campus), 2014