The Effect of 1- and 2-(1-Hydroperoxy-1-methylethyl)naphthalenes on the Liquid-Phase Oxidation of Alkylaromatic Hydrocarbons

Abstract

The properties of 1-and 2-(1-hydroperoxy-1-methylethyl)naphthalenes as initiators were studied in the liquid-phase freeradical oxidation of hydrocarbons with oxygen. 2-(1-Hydroperoxy-1-methylethyl)naphthalene was found to initiate the reaction, whereas unexpectedly, 1-(1-hydroperoxy-1-methylethyl)naphthalene was found to inhibit the reaction. The products of decomposition of the studied hydroperoxides were found to exhibit essential differences. Thermal decomposition of 1-(1-hydroperoxy-1-methylethyl)naphthalene was found to yield hydroxyaromatic compounds active as oxidation inhibitors. This fact explains the oft-reported lack of reaction in longterm oxidation of 1-isopropylnaphthalene and its disfavourable effect on the oxidation of 2-isopropylnaphthalene.

Unusual Inhibition Effect of 1-(1-Naphthyl)-1-methylethylhydroperoxide on the Liquid-Phase Oxidation of Isopropylarenes. GC−MS and Theoretical Studies of the Thermal Decomposition of 1-Naphthyl- and 1-Anthryl-1-methylethylhydroperoxides

“…We have demonstrated that hydroperoxide 1b really acts as an initiator of free-radical oxidation of isopropylarenes. We have also shown that, in contradistinction to 1b , hydroperoxide 1a inhibits the free-radical oxidation of isopropylarenes with oxygen …”

“…The differential scanning calorimetry experiments showed that their thermal stabilities are similar; the temperatures of maximum rates of decomposition ( T max ) of the 1a and 1b are close to each other (197.5 and 193.6 °C, respectively) ), the other part of hydroperoxide 1a (about 50%) being converted to an unidentified dark tarry substance .…”

“…Our kinetic measurements of the rates of oxidation of 1IPN and 2IPN in the presence of 2,2‘-azo-bis-isobutyrylnitrile and 1,1‘-azo-bis-(1-cyclohexanecarbonitrile) as initiators at 75, 100, and 110 °C showed that 1IPN undergoes free-radical oxidation with oxygen, but the reaction rate was 10−12 times lower than that of 2IPN. On the other hand, long-duration trials of oxidizing 1IPN with oxygen were a complete failure …”