Effect of ionic liquid on the thermal decomposition of cyclic organic peroxides

Abstract

The thermolysis of cyclic diethylketone triperoxide (3,3,6,6,9,2,4,5,7, DEKTP) and cyclic pinacolone diperoxide (3,6-diterbutyl-3,6-dimethyl-1,2,4,5-tetraoxacyclohexane , PDP) were studied in neat N,N-dimetyhlformamide (DMF) and in binary mixtures DMF/Ionic Liquid (1-butyl-3-methylimidazolium tetrafluoroborate, [BMIM + ][BF 4 -]). The activation parameters for the decomposition of both peroxides in DMF, correspond to a process of homolytic cleavage of one O-O bond, generating a biradical in the initial step of radical mechanism. The rate constant values (k d ) are higher for reactions performed in mixtures. A gradual increase of [BMIM + ][BF 4 -]in the reaction media generate higher k d for both peroxides (i. e. k d, DEKTP in DMF/[BMIM + ][BF 4 -] 4.0 mol L -1 is 3.3 times greater than the k d obtained for the mixture with a concentration 1.0 mol L -1 , under the same experimental conditions). The increase in decomposition rate can be associated to a more solvated and stabilized transition state when the ionic liquid is part of the reaction medium.

Solution Polymerization of Methyl Methacrylate in an Ionic Liquid Employing Cyclic Multifunctional Initiators

“…Directly comparison between both solvents, in the case of the system MMA‐IL/PDP a conversion close to 78% was observed in only 15 minutes, meanwhile with DMF it was necessary 60 minutes to reach a similar conversion value. This last behavior is sustained not only by the explanation cited before associated to diffusion problems of chains but also by the higher decomposition rate constants ( k d ) recently reported by our team for both initiators in pure ionic liquid in comparison with those reported in DMF, as shown in Table .…”

Functional Properties and Structural Characteristics of Starch–Fatty Acid Complexes Prepared at High Temperature

“…In the case of high-temperature conditions, unsaturated fatty acids absorbed energy to break π-bonds and oxygen-centered free radicals were produced. After a series of reactions, small molecules with high polarity, such as short-chain fatty acids, ketones, and aldehydes, were generated. , High temperature accelerates the change and reaction of fats and oils in practical food processing. Therefore, the effect of reaction products on the properties of starch–lipid complexes should be investigated in the future.…”