Study on the Change of Thermal Properties of XLPE Under Different Heat Aging Conditions
In this paper,commercial 110kV crosslinked polyethylene is used as the research object to observe its crystal morphology and molecular structure changes under the conditions of heat aging and hot and cold cycle aging at 160℃.Thermogravimtric analyzer(TGA),XRD(X-ray diffraction)and DSC(Differential Scanning Calorimetry)test methods are used to characterize the crystallinity,thermal decomposition behavior and thermal properties of cross-linked polyethylene under different aging conditions.The results show that the crystal deterioration degree of cross-linked polyethylene is basically the same as the deterioration law of thermal performance,but the deterioration duration of cross-linked polyethylene under the hot and cold cycle aging condition is longer and the degree of deteri-oration is smaller under the same aging time than that of the specimen under the heat aging condition of 160℃,which is attributed to the re-crosslinking process in the initial heating stage and the recrystallization process in the cooling stage after the re-crosslinking process in the cooling stage.