Water absorption behaviour in polyethylene boron nitride nanocomposites

Polymer nanocomposites, when prepared and treated carefully, have the potential to offer many advantages over the current materials used in high voltage applications. Four materials have been prepared containing 2 wt%, 5 wt%, and 10 wt% of hexagonal boron nitride nanofiller, including an unfilled material based on a polyethylene blend. The water absorption behavior was studied by measuring the change in mass in the different samples, at different humidity conditions, and using dielectric spectroscopy. Dielectric spectroscopy was used to measure both the real relative permittivity and the dielectric losses. Under dry and ambient conditions, the materials behave similarly and exhibit insignificant losses. Under wet conditions, the unfilled polyethylene does not seem to be affected, however, the nanocomposites exhibit some dielectric losses as expected. The wet samples were easily dried off and therefore behaved similarly to the originally dry samples with no apparent losses.