Determination of isopropyl peroxydicarbonate decomposition rate constant using EPR

Abstract

SJlIopsisThe decomposition rate constant, kd, of isopropyl peroxydkarbonate in toluene at 23.3"C was determined using electron paramagnetic resonance techniques (EPR). Diphenylpicrylhydrazyl (DPPH) was used to monitor the formation of radicals. Because DPPH has a strong absorption spectrum on the EPR, the accuracy of measuring small changes in the indicator concentration should be greater than measuring s m d concentrations of primary r a d i d . A value for k d of 4.5 X 1 0 ' sec-l was obtained. This is in good agreement with previously published values.