Improvement of dielectric properties of natural rubber by adding perovskite nanoparticles

Abstract

Natural rubber matrix, reinforced with several conventional stabilizer additives, was further charged with perovskite nanoparticles. Although the addition of BaTiO3 ceramic particles usually transforms a non-conducting pristine polymer into a more conductive polymer composite, in this case we use the addition of a few percent of BaTiO3 (less than 1 wt.%) to decrease the effective electrical conductivity of natural rubber (NR). This reduction has been attributed to the synergistic effect between ceramic particles and the amorphous phase of the polymer matrix, which allowed decreasing the interfacial polarisation among the NR/oxide particles interfaces. Electrical tests clearly indicate that the breakdown voltage increases and the leakage current decreases, whereas the mechanical and hydrophobicity properties of solid films improve after accurate sonication of all solid particles before pre-vulcanization process. Therefore, the dielectric elastomer becomes more insulating with the addition of nanometric oxide particles.