The autoxidation of aliphatic esters. Part 1. The reactions of tert-butoxyl and cumyloxyl radicals with neopentyl esters

Abstract

Six neopentyl esters have been selected, as models for pentaerythrityl esters used as lubricants, to study the selectivity of hydrogen abstraction by alkoxyl radicals. Kinetic and product data for the reactions of two oxygenated radicals, tert-butoxyl and cumyloxyl, with the six neopentyl esters between 408 and 438 K have been determined. They show that attack by the radicals occurs at the α- and subsequent positions on the acyl moiety as well as at the alkyl group. The selectivity of the reactions is discussed in terms of bond dissociation, steric and polar effects.