Accelerated aging of polymers using synthetic acid rain solutions

Strain type polymer distribution insulators were aged in the laboratory using an acid rain solution. Aging was accomplished with the aid of a tracking wheel using a solution concentration believed to closely match that of the natural precipitation found in a typical Northeast US environment. Throughout the aging process periodic leakage current and surface wetting measurements were obtained and found to exhibit a strong correlation. After aging the insulators were allowed to dry for varying periods up to 1400 hours. Repeated surface wetting experiments revealed that the insulators recovered little of their original hydrophobicity and insulating properties. Leakage current and discharge inception measurements were made using a variety of solution conductivities. It was found that relatively moderate increases in solution conductivity were accompanied by significant reductions in the discharge inception voltage for all insulators examined.