The Influence of Degassing on Morphology and Properties of High Voltage Cross-Linked Polyethylene Cable Insulation

摘要

Cross-linking is the process whereby the polymer structure is modified through the formation of chemical bonds between the polymer chains. The thermal and mechanical properties of PE were reported to be significantly enhanced by the cross-linking process. However, the residual cross-linked byproducts can act as impurities in a form of low molecule chains and significantly affect properties of XLPE cables. Degassing is one of the material treatment processes commonly employed in XLPE cable manufacturing to improve insulation performance. The improvement of insulation performance is always attributed to the volatilization of cross-linking byproducts. However Releasing of internal stress and recrystallization phenomenon will occur during degassing treatment. Whether releasing of internal stress and morphology change coming from recrystallization affect properties of cable insulation during degassing treatment is worthy of studying in depth.