Changes of properties of polymer insulating materials under accelerated aging test

This paper describes the experimental results of accelerated aging tests conducted on some different polymer insulating materials. Salt-fog test and UV radiation test were used to investigate the degree of surface degradation for all materials. These tests were carried out alternatively or separately till aging time achieved about 500 hours in a newly constructed chamber system that is able to control both the chamber humidity and the UV radiation. Leakage current and cumulative charge were measured through each aging cycle. The physical and chemical changes were also investigated using an electron probe micro-analyzer and an X-ray photoelectron spectroscope, respectively.