Effect of external electric field during sample preparation on dielectric properties of PVC nanocomposites

Electric cables play a crucial role in transmission and distribution systems. Polyvinyl chloride (PVC) is extensively used in cable insulation. In this work, PVC samples filled with nanosized ZnO and MgO particles are prepared. The effect of external electric field during sample preparation on the dielectric properties of PVC nanocomposites (NC) is evaluated. Accordingly, the samples are subjected to horizontal and vertical external electric fields during the preparation process. The evaluation is carried out considering different nanoparticle concentration levels. The studied concentration levels are 0.5, 1, 3 and 5 wt% for both adopted nanofiller types. Breakdown strength of the prepared NC samples is measured according to American society for testing and materials standard. Also, relative permittivity and dielectric loss of the prepared NC samples are measured. The evaluation is carried out considering horizontal and vertical electric fields. The obtained results show significant effects on the dielectric properties of the tested samples. Hence, the results show that the external electric field decreases relative permittivity and dielectric loss; however, it increases the breakdown strength of PVC NC. Applied horizontal electric field during sample preparation gives more improvement in dielectric properties of PVC NC compared to vertical electric field. Finally, the interpretation of the obtained results is highlighted and discussed.