Direct current breakdown properties of polypropylene nanocomposites containing magnesium oxide

Abstract

Polypropylene (PP) has promising electrical insulation properties as with its high thermal stability and voltage breakdown strength. Nevertheless, PP has a high degree of rigidity, making it difficult to be utilized directly as cable insulation. In this experimental work, ethylene-propylene-diene monomer (EPDM) has been mixed with isotactic polypropylene (PP) and the brittleness property of PP has been successfully modified. A nanofiller of magnesium oxide (MgO) has been embedded in a 50% PP and 50% EPDM blend. The various low loadings of MgO have been added to PP/EPDM nanocomposites to enhance the thermal and direct current (DC) breakdown strength of PP/EPDM nanocomposites. It reveals that the melting behavior of PP/EPDM nanocomposites is stable even after the addition of MgO. On the other hand, the addition of MgO greatly impacts the DC breakdown strength of the nanocomposites. To achieve the desirable electrical properties, the optimum content and dispersion of nanoparticles are crucial factors to be considered carefully.