Antioxidant action of 1,4-phenylenediamine antidegradants in selected liquid hydrocarbons

Abstract

The antioxidant action of six N,N'-disubstituted derivatives of 1,4-phenylenediamine in the oxidation of tetralin, cyclohexene, squalane and squalene initiated with 2,2'-azobis(isobutyronitrile) at 60 °C was investigated. The amines under investigation acted as very strong antioxidants. The effect of substitution in positions N,N' on effectiveness is not very essential; it depends on the type of the substrate and does not make possible an unambiguous formulation of the relation between structure and effectiveness. It has been proved unequivocally that retardation of oxidation after completion of the induction period is a result of the formation of derivatives of benzoquinone diimine. The retardative action also is affected by the type of the oxidized hydrocarbon.