Mechanisms op antioxidant action op organic phosphorus compounds

Abstract

The antioxidative activity and the mechanisms of antioxidant action of alkyl, aryl, cyclic and sterically hindered phosphorous acid esters and amides have been studied. The chain-breaking efficiency of phosphites is shown to depend on the structure of both the phosphorus compound and the substrate to be stabilized. At moderate temperatures aryl phosphites act as primary antioxidants only in the autoxidation of substrates which are not very reactive towards peroxyl radicals. The chain-breaking efficiency is related to the nature of transformation products formed in the reactions of phosphites with alkylperoxyl and alkoxyl radicals. These products have been identified in some model reactions. All phosphorus(III) compounds destroy hydroperoxides and so are able to function as secondary antioxidants. -Phenylene phosphite esters and amides react with hydroperoxides to give hydroxyphenyl phosphates which are efficient chain-breaking agents. © 1983 IUPAC