Dynamics of temperature dependence of the dielectric properties of a nanocomposite material based on linear polyethylene in the vicinity of the percolation transition

Abstract

Within the frequency range of 30 to 105 Hz and temperatures of 18 to 80 °C, the dielectric properties of linear low-density polyethylene with impurities of flame retardant (20 wt.%) and multilayer carbon nanotubes (1.5 wt.%) were investigated using the oscilloscopic method. This concentration value of carbon nanotubes slightly exceeds the concentration of nanotubes (1%), at which the percolation transition begins for the dependence of the polymer electrical conductivity on the content of nanotubes. It has been shown that the frequency dependence of electrical conductivity can be approximated by two exponential dependences. It has been found that when the sample is cooled, changes in the values of dielectric permittivity and electrical conductivity do not occur in the same way as when heated. The temperature dependences of conductivity for low (102 Hz) and high (104 Hz) frequencies have been obtained.