Cyclic organic peroxides thermal decomposition in the presence of CuFe2O4 magnetic nanoparticles

Abstract

The effect of magnetically recoverable CuFe2O4 nanoparticles on thermal decomposition of acetone and pinacolone cyclic organic diperoxides, and acetone triperoxide was studied. Ethanol, toluene or ethylbenzene were used as reaction solvents, the initial peroxide concentration was ca. 0.02molL−1 and the amount of heterogeneous catalyst added was ca. 0.5mgmL−1. CuFe2O4 nanoparticles, obtained according to the citric acid-aided process, greatly accelerates the thermal decomposition of methyl substituted cyclic peroxide, but in the case of pinacolone diperoxide only slightly catalytic effects can be detected, probably due to the presence of the bulky tert-butyl substituent in the proximity of the OO bond. This heterogeneously catalyzed reaction can be explained by a free radical mechanism which involves the initiation reaction on the catalyst surface. The products detected (ethane, 2,2-dimethylpropane, ethylbenzene, bibenzyl and 2,3-diphenylbutane) can be interpreted in terms of the initial OO bond homolysis catalyzed by copper ferrites to form an iron peroxo radical species which later undergoes CO and CC bond cleavage. The reduction of the reaction temperature in the styrene and methylmethacrylate polymerization processes could be the main application of the results obtained in the present work, where the thermal decomposition of multifunctional cyclic peroxides in the presence of copper ferrites can be reached decreasing the working temperatures.