Studies on electrical tree and partial discharge properties of PE/MMT nanocomposites

In this paper polyethylene/montmorillonite nanocomposites are made by melt intercalated process. Electrical tree and partial discharge properties of original polyethylene and polyethylene/ montmorillonite nanocomposites are respectively investigated by the combined test system of electrical tree initiation and partial discharge measurement. The results show that most of electrical trees in polyethylene/ montmorillonite nanocomposites samples are bush-shaped, the length of electrical trees are about 230 mum, and the maximum partial discharge pulse height increases up to 140 pC at first 60 min, then partial discharge pulse height decreases gradually, almost none of discharge signal can be observed at 120 min. However, in original polyethylene samples, most of electrical trees are branch-shaped, the length are about 400 mum, and the maximum partial discharge pulse height continually increases up to 180 pC at the electrical stress applied to the samples for 120 min.