Study on XLPE Temperature-Frequency Aging Based on Combined Analysis of Laser Induced Breakdown Spectroscopy and Gas Chromatography

The aging mechanism of polymer materials such as cross-linked polyethylene (XLPE) has been paid close attention. This paper built a temperature-frequency heat aging platform, which is compared with constant temperature heat aging. The acceleration efficiency of XLPE frequency change heat aging and constant temperature heat aging was compared by Fourier transform infrared spectroscopy. Combined with laser induced breakdown spectroscopy (LIBS) and gas chromatography, the dynamic characteristic of XLPE aging process was explored and the thermal aging mechanism of XLPE and other polymer materials was revealed. It found that the aging effect of frequency-induced heat aging on XLPE was more serious, and the artificial accelerated aging time can be shortened by this method. The content of C, H and O elements increased with the increase of aging time, showing three processes of gradual-increasing-smoothing, corresponding to the three aging stages of the material. The results of gas chromatography showed that XLPE mainly released isobutylene gas in the early stage of aging, and the content of oxygen-containing organic compounds released during the middle and late aging period increased and the isobutylene content decreased.