Dielectric response of LLDPE/Clay nanocomposite melt compounded from a masterbatch

In this paper, linear low density polyethylene (LLDPE) specimens containing from 0 to 5% of nanoclays were prepared from a commercially available premixed LLDPE/nanoclay masterbatch containing 50% wt of nanoclay. The masterbatch was diluted to the desire concentration by the addition of LLDPE pellets along with various amount of compatiblizer in order to achieve the best possible dispersion of the nanoclay platelets. The dielectric response of the compounded samples was investigated using a combination of time and frequency domain spectroscopy in order to cover a wide frequency window. Both techniques were in good agreement when the time domain data was transformed into the frequency domain. Despite the low concentration, the addition of the dispersed nanoclays lead to a significant alteration of the material dielectric response in the form of the appearance of various interfacial relaxation processes and an increase of charge carrier transport within the insulation material. Moreover, the onset of nonlinear charge transport process was observed at moderate fields for specimen containing a relatively low level of nanoclays.