Kinetic Features of Methylinoleate Oxidation in Micelles of Sodium Dodecyl Sulfate

By combining kinetic and physicochemical methods with computer simulation, new information was obtained on the oxidation of methyllinoleate (LH) in micelles of sodium dodecyl sulfate (SDS) at 303 K. The dynamics of the process is related to the nature of the change in the volume of the micellar phase (V_mic). A gradual increase in V_mic leads to a decrease in the concentration of the oxidation substrate. This change occurs not only due to chemical reactions, but also due to a change in the volume of the microreactor in which the chemical transformation takes place. The accumulation of hydroperoxides inside those micelles in which LH is oxidized leads to the transformation of their structure and the formation of mixed micelles. Kinetic analysis shows that chain termination can occur by a mixed mechanism. The reaction order according to the initiator varies from 0.61 to 0.71. Leading oxidation chains, peroxy radicals ( \({\text{LO}}_{2}^{\bullet }\) ), are involved in both quadratic and linear termination. Linear termination occurs with the participation of hydroperoxyl radicals ( \({\text{HO}}_{2}^{\bullet }\) ). The formation of \({\text{HO}}_{2}^{\bullet }\) is due to the reaction \({\text{LO}}_{2}^{\bullet }\) → product + \({\text{HO}}_{2}^{\bullet }\) occurring in the organic phase. The resulting \({\text{HO}}_{2}^{\bullet }\) radicals goes into the aqueous phase, where the rate of their disproportionation is very low. Formally, this has been observed as a linear chain termination.