Enhancing the Breakdown Strength of Polypropylene Nanocomposites Through Filler Hybridization

ABSTRACT This research examines the effects of single and hybrid nanofillers on the structure and breakdown properties of polypropylene (PP)‐based nanocomposites (NCs). Single nanofillers, that is, titanium dioxide (TiO ₂ ) and montmorillonite (MMT) clay, and a hybrid nanofiller, that is, MMT‐TiO ₂ (in a ratio 1:1 by mass), synthesized by a sol–gel method, were incorporated into PP at different loadings. The effect of these nanofillers on the microstructure and breakdown strength of resulting PP‐based NCs was evaluated. The results reveal that, successful hybridization of MMT‐TiO ₂ nanofiller was achieved, where nano‐TiO ₂ successfully penetrated in between the galleries and on the surface of MMT. At low nanofiller loadings, the alternating current breakdown performance of the hybrid filled PP system was higher than the pure PP and single nanofiller systems. Also, the direct current breakdown strength of the hybrid filled PP system was higher than the single nanofiller PP system. Furthermore, finite element analysis showed that the electric field distribution of hybrid filled PP was more uniform compared with PP filled TiO ₂ . Specifically, these results show that hybridization of two different geometrical fillers is an effective strategy for improving the electrical properties of PP NCs.