A study of accelerated oxidation of XLPE

Although the oxidation processes in polyethylene have been the subject of several studies, there remain many unknowns, especially with respect to the aging of high-voltage cross-linked PE (XLPE) cables. These materials contain, among other additives, an antioxidant and a cross-linking agent whose presence significantly modifies the oxidation processes. In order to evaluate the influence of these additives on accelerated thermal aging, molded PE samples with different additive concentrations were subjected to high temperatures in air. The customary chemical techniques used to measure the additive content in PE do not give reliable results in XLPE. In this paper, it is reported that the content of sulfur-containing antioxidants in XLPE can be determined precisely by neutron activation analysis.