Abstract
The structure of dielectric materials is one of the main important parameter, which determines the durability of products. The degradation process runs differently in various types of polyethylene, because the macromolecules present different level of branching, different crystallinity grades, different chemical resistance. The dissimilarities between the resistance on ageing of different sorts of polyethylene are depicted by FTIR analysis, chemiluminescence determinations and the measurement on electrical resistivity. The consequences on the long term service under g-irradiation degradation are discussed. Keywords: polyethylene materials, degradation, FTIR, chemiluminescence, electrical properties