Effect of Dibenzyl Disulfide Corrosion on Accelerated Thermal Aging Crosslinked Polyethylene Cable Materials with Copper Core and Insulation Layer

Abstract

Crosslinked polyethylene (XLPE) cable has been widely used and studied with its specific failure mechanism. Among them, although thermal aging of XLPE insulation materials has been widely studied, the effect of accelerated thermal aging on the sulfur corrosion of XLPE cable has not been studied much. For further understand the mechanism of sulfur corrosion, the accelerated thermal aging method was taken with 200 mg/kg DBDS based on the distinguish of temperature. The macro and micro analysis contrast test before and after corrosion were also taken to investigate the morphology difference, the element distribution, the influence of thermal aging and DBDS addition the corrosion of copper core, and the assessment of insulation layer was also carried out by Fourier transform infrared spectra and spectroscopy, scanning electron microscopy to distinguish the microstructure and composition. Under the accelerated thermal aging experiment with DBDS, both copper core and insulation layer of sample No. 1 exhibit the most serious corrosion and aging condition. On the surface of the copper core, the DBDS-Cu complexes decompose to produce Cu2S and the temperature has a direct effect on this reaction. The insulation layer of sample No. 1 showed the most severe aging situation, with characteristic peaks of carbonyl appearing at 1720 cm-1 in the Fourier transform infrared tests and more defects, holes and cracks found in spectroscopy, scanning electron microscopy images.