Nanocomposites based on magnesium-oxide/aluminum-nitride/polypropylene for HVDC cable insulation

Abstract—Polypropylene (PP) with high thermal stability and good electrical properties, has attracted much attention for its potential to take the place of cross-link polyethylene (XLPE) as HVDC insulation because PP is more easily recycled than XLPE due to its thermoplasticity. Due to the adverse effect of electric field reversal under HVDC application, there is a need to find the new polymer insulation material with higher thermal conductivity and good electrical performance. This paper investigates the effect of introducing aluminum nitride (AlN) and magnesium oxide (MgO) into PP on the electrical properties of the resulting the new nanocomposites. In the sample preparation, AlN and MgO were surface-modified by KH570 (γ- methacryloxypropyltrimethoxy silane) and then introduced into PP by the solution method to manufacture the nanocomposite materials. The measurements made were the voltage breakdown characteristics and the DC conductivity. The results obtained show that the combination of AlN and MgO can slightly decrease the DC conductivity of PP/AlN/MgO nanocomposites compared with pure PP. The breakdown strength was slightly decreased. which shows that the adverse effect of AlN on the electrical performance of PP can be compensated by introducing MgO nanoparticles. Hence, the new polymer with high thermal conductivity and good electrical properties could be manufactured by combining two kinds of nanoparticles.
Keywords — nanocomposites, magnesium-oxide, aluminum-nitride, polypropylene, electrical performance.