Effect of dioctyl phthalate (DOP) plasticizing agent on the dielectric properties of PVC insulation

The purpose of the paper is the investigation of the dielectric properties with respect to the plasticizer content in PVC materials. This polymer type is widely used as insulating and jacket material of cables in different areas of electric power engineering e.g. power plants. The dielectric relaxation of the synthetic plastics is a well-known phenomenon. During the measurement of insulation resistance, the development of steady state current requires quite long time due to the slow polarization processes in polymeric insulations. The investigation has been executed on thin film PVC samples with different plasticizer content and the dielectric processes have been measured by insulation resistance and voltage response measurement methods. By the usage of these parallel measurements, theory of slow polarization processes can be studied more precisely. In PVC the parallel methods lead to more exact results than if only one of measurements is used.