Morphology change and tree initiation of polyethylene

Electrical trees are greatly influenced by the morphological structure in semi-crystalline polymers. In this paper, samples of polyethylene (PE) films have been annealed. The electrical tree initiation voltages of these samples also have been measured. It was found that the thickness of lamellae is the important parameter that affects the tree initiation. It was also found that the thermal stability could be related to the thickness of lamellae. It was considered that the larger the thickness of lamellae, the higher the thermal stability, which results in the more difficult tree initiation.