Water tree growth processes in XLPE

Water trees as degradation products contain information about the aging process (es). The likelihood of oxidation, ion diffusion, and chain scission occurring during water tree growth in polyethylene insulation is discussed. The possible roles of the three processes are discussed. They cooperate in water tree growth, but may compete with respect to reaction products. It is also pointed out that antioxidants may play a dual role if they can be easily oxidized to ionic species. It is concluded that, with testing, care must be taken to accelerate the right process, because many parameters influence the growth rate of water trees.<>