Influence of biodegradable matrix on electrical conductivity of cooper filled composites

Abstract

The results of experimental studies of the properties of composite materials based on Poly (lactic acid) (PLA) and Poly (3-hydroxybutyrate) (PHB) matrices filled with electrolytic copper powder, having very high dendritic structure, are presented in this manuscript. Copper powder volume fractions used as filler in all prepared composites were varied in the range of 0.5-6.0 %(v/v). The samples were prepared by hot molding injection at 170°C. Influence of particle size and morphology, as well as influence of matrix type on the conductivity and percolation threshold of the composites were examined and characterization included: Electrical conductivity measurements using Impedance Spectroscopy (IS), Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS) and Fourier-transform Infrared Spectroscopy (FTIR). Presence of three dimensional conductive pathways was confirmed. The obtained percolation threshold of 2.83 %(v/v) for PLA and 3.13 %(v/v) for PHB composites was measured, which is about three times lower than the one stated in the literature for similar composites. This property is ascribed to different morphology of filler used in investigation.