On Increasing the Inhibiting Property of Amine Antioxidant in Contact With Copper and Its Compounds

The mechanism of increasing efficiency of amine-type antioxidant (AO)-N-plenyl-2-naphthylamine (Neozon D)—used to inhibit oxidation of polyethylene (PE) under conditions of contact between the polymer and metallic copper has been investigated. It has been learned experimentally, that the hypothesis of formation of complex compounds by reaction of AO and copper-containing products—resulted from contact oxidation of PE melt on copper—is invalid. A different mechanism of raising the inhibiting efficiency of amine AO is suggested, according to which copper catalyzes transformation of Neozon D to nitroxyl radicals. The latter are excellent inhibitors for oxidative transformations and appreciably enhance polymer resistance to oxidation. An amine-type AO can be converted to nitroxyl radicals in two ways: (i) before AO is added to the polymer; (ii) during direct contact between the AO and metallic copper (i.e., copper as metal) which is a component of the metalopolymeric material (e.g., polymer-coated substrate; filler particles introduced into a polymer) that is subjected to oxidation. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010