Abstract
UDC 539.21;537.312.7
This work concerns the studies placing and contacting features of thermally exfoliated graphite (TEG) particles with different dispersion levels in compression as well as the analysis of the effect of the carbon filler morphology on electrophysical properties of nanocomposite materials (NCMs) with fluoroplastic. The electrical resistance and dielectric permittivity of the NCMs were studied using four-, three- and two-electrode circuits. It has been found experimentally that the percolation threshold, calculated by the concentration dependencies of the electrical resistance values, is shifted towards the area of lower filler concentrations – from 12.5 to 5.2 vol.%, with the increase of the mean value of TEG particles cross-section from 40 to 500 micrometers. This data were used to find t critical indices for nanocompositions and to establish laws of formation of a current-conducting cluster in the polymer matrix. It has also been shown that a decrease in the dispersion level of the carbon component in NCMs affects polarization processes of its particles and leads to its higher dielectric permittivity.
Keywords: thermally exfoliated graphite, fluoro-plastic, nanocomposite material, resistivity, dielectric permittivity.