Determinations cinetiques par analyse microcalorimetrique differentielle. XIII. Decomposition, catalysee par l'ethyl-2 hexanoate de cuivre, du perbenzoate de t-butyle en solution

Abstract

The kinetic study of the decomposition of tert-butyl peroxybenzoate in the presence of copper 2-ethyl hexanoate as a catalyst was performed using differential scanning microcalorimetry. The experimental data were obtained at several initial concentrations of peroxyester and their analysis led to the rate law of the slowest (governing) step of the whole process. The form of this rate law, which is of the Michaelis—Menten equation type often used in enzymology, leads to the conclusion that the decomposition proceeds via a peroxyester—metal salt intermediate complex. As for the peroxybenzoate stability, it is obvious that it is strongly lowered in the presence of the copper salt; the reaction half time at 125°C is lowered from 1 h to 1 s.