Reliability Study on Rapid Evaluation of Thermal Aging Life of Cross-Linking Polyethylene by Thermogravimetry

Thermogravimetry is used to study the thermal degradation process of cross-linking polyethylene material under two atmospheres of nitrogen and air,referring to JB/T 1544—2015,ASTM E1641-07—2012,and ASTM E1877-00—2015 standards in combination with conventional aging methods and Arrhenius empirical formula,using5% weight loss as the endpoint of XLPE service life. The thermal service life under the air atmosphere was respectively evaluated by the constant temperature method and the heating method,and the thermal life equations lnt = 14 970/T-23. 8 and lgt_f= 6 581. 6/T_f-10. 574 were built. Finally,combining the actual life,estimation results of thermal life at 90 ℃,and the correlation coefficients of the thermal life equation,the two methods are reliable.