Conduction mechanism and dielectric properties of PP/EVA/MWCNTs nanocomposites in the presence of PP-g-MA comatiblizer

The role of PP-g-MA compatibilizer for improving the dielectric properties of PP/EVA blends for the first time reported in this study by considering the mechanism of conduction. A cocontinuous morphology for this system was observed by FE-SEM. The interfacial localization of MWCNTs was validated by AFM and FE-SEM images. The dielectric properties revealed that dielectric constant was increased by increasing the PP-g-MA content to the saturation point of interfacial localization due the better function of interfacial polarization in regards to the increment of MWCNTs contribution in interconnected pathways as polarizable dipoles. By passing the saturation point (at 20 v%), the significant increase was observed in dielectric constant due to the existence of extra compatibilizer in PP for improving the dispersion and increasing the MWCNTs nano-capacitors amount. The increasing trend in loss dielectric constant vs frequency suggested that tunneling mechanism was determinant conduction mechanism by introducing the compatibilizer to the PP/EVA system as compared to the direct contact mechanism. The loss tangent graph showed that the current leakage was decreased by increasing the compatibilizer content due the vanishing MWCNTs agglomerated structures. A specific applied outcome of the study was to reduce the percolation threshold of PP/EVA blend from 1.8 vol% without compatibilizer to 0.95 vol% with compatibilizer under certain mixing conditions.