Effect of organoclay loading on the dielectric properties and charge dynamics of a PP‐rubber nanocomposite

The addition of organoclay to a polypropylene‐rubber (PP‐rubber) blend, primarily introduced to compatibilise the immiscible polymer blend, invokes contrasting dielectric and charge dynamic behaviour depending on the filler loading level. The authors report that at 0.5 wt.% loading, the organoclay decreases the DC conductivity, causes no significant dielectric losses, makes no significant difference to the space charge results compared to the unfilled system, and increases the reproducibility of the breakdown strength results, and hence the reliability of the material. These somewhat surprising results, contrasted by measurements of samples with 2.5 and 5 wt.%, lead us to conclude that trace amounts of organoclay improve the otherwise immiscible polymer blend making organoclay a suitable additive for HVDC applications.