A study on the space charge formation in XLPE

Space-charge formation in crosslinked polyethylene (XLPE) was examined using the charge profiles of XLPE specimens crosslinked at different temperatures. Negative charges were detected in the vicinity of the positive electrode of specimens cross-linked at temperatures exceeding 180/spl deg/C. After the crosslinking byproducts were removed, the heterocharge disappeared and remained undetected even after the specimens were soaked in acetophenone. Charge profiles were also obtained for XLPE specimens containing an antistatic agent, which has the function of absorbing moisture. The heterocharge was detected clearly in these specimens, and although the heterocharge disappeared after the decomposition products were removed, the heterocharge was detected again when the specimen was soaked in acetophenone. It is concluded that the small amount of moisture in XLPE is responsible for heterocharge creation.