Influence of antioxidants on polyethylene chemical crosslinking reaction

The influence of antioxidants on the chemical crosslinking of crosslinked polyethylene (XLPE) was investigated. Experiments were conducted using XLPE specimens crosslinked at various temperatures with added phenolic, sulfur-type and amine-type antioxidants. Specimens were characterized by measuring the gel fraction and the content of crosslinking byproducts, acetophenone, cumyl alcohol and /spl alpha/-methyl styrene. It was found that sulfur-type antioxidant has the strongest influence on the decomposition of cumyl alcohol, whereas the amine-type had only a minor influence. Taking the data regarding the crosslinking temperature dependence of the crosslinking byproduct content into consideration, the mechanism of antioxidant action in the crosslinking reaction is examined.