The Course and Mechanism of Autoöxidation Reactions in Olefinic and Polyolefinic Substances, Including Rubber

Abstract

The tendency of olefins to absorb molecular oxygen increases rapidly with increase in unsaturation. In monoolefins absorption is usually very slow unless it is actively promoted by irradiation, by the use of temperatures above room-temperature, or by chemical catalysts; in dienes and trienes it usually becomes considerable in diffused daylight; and in higher polyenes it tends to occur unpreventibly and excessively. The strong tendency towards oxidation shown by polyenes appears to be shared by unconjugated and conjugated substances alike, although the precise courses of reaction are probably somewhat different in the two cases. In the present paper attention is focussed mainly on monoolefinic and unconjugated polyolefinic substances.

The Sulfurization of Unsaturated Compounds.

“…Farmer and coworkers (19,20,21) evolved a theory of the mechanism of sulfurization which is worth much consideration. They based it on their own and other researches on oxidation.…”

“…The normal mechanism of the addition of halogens to a double bond is ionic, but their substitution on the -methylene group is believed to be through free radicals (21). Farmer ascribed a free-radical mechanism to the peroxidation reaction.…”

A study on the thermal degradation of rubber in dilute solutions

“…They reported that two types of peroxide exist, the more stable of which has an energy of activation of 20-25 kcal./mole. Farmer et al 17 and Bevilacqua,18 working with oxygen derivatives of model compounds, have presented mechanisms for degradation through peroxide and hydroperoxide rupture and, in certain cases, through formation of epoxide.…”

Avaliação da estabilidade oxidativa de misturas binárias de biodieseis metílicos obtidos a partir de óleos de soja, algodão, canola, girassol, milho e residual

“…A interpretação de como ocorre o processo oxidativo em um ácido graxo está ilustrado na Figura 8, demonstrando a proposta de Farmer et al em seu trabalho. A ilustração detalha uma seqüência de reações para a explicação do processo oxidativo de um lipídeo, especificamente do éster do ácido linoléico (éster de ácido graxo insaturado) [70].…”