A modified method in dielectric research of carbon black rubber compounds

The dielectric response of carbon black filled styrene butadiene rubber (SBR) composites was studied by applying a new experimental set-up, In contrast to the common method placing the rubber compound between the electrodes two additional insulation layers were inserted into the test condenser. The insertion of the insulating layers improves the repeatability of the measured data and permits to distinguish the characteristic properties of different compounds. Dielectric constant and dielectric loss of this system were recorded in a frequency range from 20 Hz to 1 GHz for different types of carbon blacks and various filler contents below and above the percolation threshold. The results are discussed by means of the Maxwell-Wagner model for a layered heterogeneous system.