2019 | vol. 67 | nr. 1 | art. 8

Dielectric and Morphostructural Characterization of some Types of Polypropylene Composites /Metallic Nanopowders

Alina-Ruxandra CARAMITU, Virgil MARINESCU, Sorina MITREA, Mihaela ARADOAIE, George-Andrei URSAN
By extrusion and injection, the composite samples were prepared the polypropylene (PP) based composites with a filler of the nanostructured alumina powder and iron of relatively small size (50 nm) and of about large size (over 750 nm). Thermal analysis determinations - DSC curves - indicated that the polypropylene type used in order to achieve the composite can be processed (by extrusion and / or injection) without the risk of thermal degradation at temperatures between 165 C (end of the melt process) and 270 C (the first thermooxidation process). Determinations achieved by the dielectric spectroscopy technique have shown that the PP based composite materials with metallic nanopowders filling have dielectric losses higher than pure polypropylene (reference). The highest increases in tgδ up to 1.8 times being recorded in the case of 50 nm nanopowders with high specific surface area (over 20 m2/g). Also, an increase in the electric conductivity of polypropylene based composites with filler of metallic nanopowders was observed at increase the composite metal content, the growth rates being systematically higher for powder with higher particle sizes. At all concentrations of metallic filler in the composite, the composites conductivity increases at frequency increase, which may be due to the film effect.
Keywords: polypropylene, iron nanopowder, aluminium nanopowder, composite, dielectric loss, conductivity
To cite this article: CARAMITU, A-R., MARINESCU V., MITREA, S., ARADOAIE, M., URSAN G.-A., “Dielectric and morphostructural characterization of some types of propylene composites /metallic nanopowders”, Electrotehnica, Electronica, Automatica (EEA), 2019, vol. 67 no. 1, pp. 61-67, ISSN 1582-5175.