Properties of Aluminum Filled Polypropylene Composites

Abstract

Polymers and metals have a long history of use in diverse applications. Metal filled polymer composites are nothing new, as the first attempt to combine these two classes of materials was made in the earlier years of the 20th century. The composites made by incorporation of powdery metal fillers into thermoplastic polymers combine the advantageous properties of metals and plastics. They offer light weight, resistance to corrosion, rapid fabrication rates and a wide range of moduli etc. In the present study, aluminum filled polypropylene (PP) composites with different filler particle shapes and filler loadings varying from 0% to 55% by volume were prepared. The effect of filler loadings and filler particle shapes on the properties of the composites was identified. The percolation concentrations were between 15% and 30% by volume for flaky aluminium filled PP composites, whereas with spherical aluminium particles the percolation concentrations were between 30% and 45% by volume. A steep decrease in electrical resistivity and a pronounced decrease in tensile strength and elongation at break on addition of the metal filler occurred for all investigated systems. Thermal characterization studies showed that the addition of aluminium reduced the crystallinity of the polypropylene and slightly retarded its thermal degradation. High void levels must be taken into account in evaluating the results.