Thermal Aging ofPolyvinyl chloride

Thispaperreports onthestudy ofthe thermal aging ofthepolyvinyl chloride usedinhigh voltage cables. Thisstudy shows that thermal aging changes theelectrical properties ofthematerial. We notice that thehigher theaging temperature is, the moreimportant istherateofdegradation ofthe insulator. Atthebeginning oftheaging process, there isaloss oftheplasticizer. Whenthetime ofexposure toheatbecomesimportant, thedegradation is attributed toaprogressive consumption ofstabilizer withachange incolour andarelease ofchloridric acid. Thisphenomenon causes also cross-linking and reduction ofinsulator volume. Theshrinking andthe change incolour aretheconsequences ofthematerial degradation.