Material PropertiesEffect of selective localization on dielectric properties of boron nitride nanofiller filled linear low density polyethylene (LLDPE)/silicone rubber (SR) blends

This study investigated the performance of thermoplastic elastomer (TPE) nanocomposites based on linear low density polyethylene (LLDPE) and silicone rubber (SR) blends filled with boron nitride (BN) nanofiller for application as high voltage insulators. The investigation focused on the effect of different mixing sequences applied during the preparation of the nanocomposites on various dielectric properties. BN nanofiller were introduced into LLDPE/SR by using three different sequences; LLDPE + SR + BN, LLDPE + masterbatch-SR/BN and SR + masterbatch-LLDPE/BN. The dependence of the phase morphology on the mixing sequence was investigated through electron microscopy observations. The results showed that the presence of nanofiller increased permittivity, loss tangent and dielectric breakdown strength of the LLDPE/SR nanocomposites. The samples prepared with masterbatch-SR/BN exhibited encapsulation structure and showed the lowest permittivity and loss tangent and the highest dielectric breakdown strength compared to the other two mixing sequences, which generated separated dispersion structure.