Effects of SiO2 nanofillers on Polarization and Depolarization Current (PDC) of LLDPE-NR nanocomposite insulating materials

Polymeric nanocomposites are increasingly adopted for replacing conventional insulation to provide enhanced performances such electrical and mechanical properties. Polarization and Depolarization Current (PDC) measurement is an efficient and effective diagnostic technique based on time domain measurement to monitor the dielectric behaviour. One of the main targets of the research in the field of polymer nanocomposite dielectrics is to obtain new materials with improved dielectric properties. In this paper the conductivity variation of LLDPE nanocomposite are investigated for formulations of natural rubber (NR) blends nanocomposites obtained from polyethylene filled with nanoparticles of SiO₂ by using Polarization and Depolarization Current (PDC) measurement technique. The experiment was conducted to find PDC pattern and conductivity variations of each sample. LLDPE-NR/SiO₂ at 5 %wt of nanofiller was found to be the best composition for HV insulation in term of lowest polarization and depolarization current values and lowest conductivity. The results show that additional certain percentage of nanofiller and natural rubber into LLDPE based material had improved dielectric strength of the material.