Influence of the presence of medium-soft paraffin wax on the morphology and properties of iPP/silver nanocomposites

Abstract

The aim of this study was to investigate the presence of wax, different Ag nanoparticle contents, and different cooling rates from the melt, on the morphology, thermal and electrical conductivity, and dynamic mechanical properties of iPP. The Ag particles were well dispersed in the polymer, and formed nucleation centres for the crystallization of iPP. They were also well dispersed in iPP/wax, but they were located in the wax phase which was dispersed between the iPP spherulites. Generally the extent of filler agglomeration increased with increasing filler content. The Ag particles, whether in the iPP or wax phase, had little influence on the crystallinities and melting temperatures of iPP. The presence of Ag particles in iPP had little influence on its modulus, but the presence of both wax and Ag particles significantly improved the modulus of these nanocomposites. The thermal and electrical conductivities of the samples more significantly improved when both wax and Ag were present. With increasing Ag particle contents in both iPP/Ag and iPP/wax/Ag, the thermal conductivities increased, but leveled off at higher filler contents, while the electrical conductivities continuously increased with increasing filler contents. The slowly cooled samples had higher crystallinities than the quenched samples and therefore they were more thermally conductive than the quenched samples.

Keywords

• Nanocomposites
• Isotactic polypropylene
• Paraffin wax
• Morphology
• Conductivity