Unveiling the synergistic effect of zinc oxide and carbon black nanoparticles on the dielectric properties of vulcanized natural rubber

Flexible nanocomposite materials were prepared by introducing Zinc Oxide (ZnO) and Carbon Black (CB) as nano-fillers separately into vulcanized natural rubber (NR). The impact of curing agents and filler integration on the structure and electrical characteristics of NR was thoroughly examined. Electrical properties such as dielectric constant, dielectric loss, and ac conductivity were assessed. Pure NR exhibited higher dielectric properties and ac conductivity compared to NR cured with pentane-1,5-deylidenediamine (PDD), which gradually decreased up to a certain threshold due to the immobilization of non-rubber constituents. Dielectric Constant of pure NR decreases from 148.81 to 6.87 upon the addition of 2 ml crosslinking agent into NR. Furthermore, NR composites filled with CB demonstrated lower dielectric properties compared to those filled with ZnO, likely attributed to the polar nature of ZnO. Dielectric Constant of cured NR was increased and exhibited 20.7 for the NR composite with 0.06 % ZnO. The surface roughness of the resulting nanocomposites was analyzed using optical profilometry, and its correlation with dielectric and ac conductivity was investigated.