Antioxidant and its reaction products as charge trapping centres in crosslinked polyethylene

The present work aims at evaluating the propensity of 4,4'-thiobis(2-tert.butyl-5-methylphenol) type antioxidant and three of its reaction products for acting as charge trapping centres. Model materials have been realized in this respect. The technique applied consists in analyzing charge recombination-induced luminescence (RIL) following bipolar charge implantation at the surface of the material by interaction with a plasma discharge. The method provides the luminescence spectrum of species acting as charge recombination centre. It is shown that, broadly, luminescence signatures of XLPE are more relevant to antioxidant-related chemicals than to crosslinking by-products ones.