The thermal and dynamic aspects of change in electrical conductivity of high-strength polyethylene filled with carbon black

The mechanism of electrical conductivity of composite materials based on polymers filled with carbon black, has a complex character. This character is conditioned by the surface properties of carbon black, the interaction of the filler particles with the polymer and the structure formed in the polymer when exposed to electric fields. Due to the complex structure of the system of particles of carbon black in the polymer matrix, a theoretical calculation of the electrical conductivity of a composite with a given concentration of the filler can be challenging. The results show that the temperature dependence of the resistance (conductivity) HDPE filled with carbon black, change over time and depend on the sample history. In the analysis of possible changes in the process of measuring the resistance in the sample a thermodynamic approach is used. The resulting equation is in quite satisfactory compliance with experimental results. From the equation the numerical values of the parameters that determine the conductivity property HDPE samples with soot. The model of time-temperature dependence of the resistance of the polymer composite lets conclude that the conductivity of such systems largely depends on the interfacial conformational states border layers section of polymer-filler and the polymer matrix. Such states are determined by external conditions and have a relaxation character. The method of the periodic influence of the electric field on the system HDPE allowed to reduce the resistance for a few more units than under the continuous action of the field during the exposure of the sample under isothermal conditions. This fact argues in favor of the proposed model. In this paper the effect of temperature change on the change in resistance of the samples of high-density polyethylene-filled carbon black under different measurement conditions is investigated. It is shown that the conductivity measurement conditions have effect on the results. The thermodynamic model of the influence of measurement conditions on the resistance of the composite material is proposed in the process of analyzing the results.