Peroxides. Part 11. Iodimetric analysis of dialkyl and dicumenyl peroxides

Abstract

Dialkyl peroxides, the most stable and least reactive of the peroxides, slowly react iodimetrically at elevated temperatures. A simple rapid thermal reaction of dialkyl peroxide with iodide ion was developed with either HClO₄ or Fe³⁺ as catalyst. The iodimetric titrations gave quantitative results in 2–20 min, depending on the catalyst concentration, temperature and peroxide structure. The order of decreasing peroxide reactivity and increasing stability based on structure was dialkyl, tert-butyl alkyl, diaralkyl, di-tert-butyl. The dialkyl peroxides, the most reactive in this analytical procedure, did not require catalysis, but quantification of this class of peroxides was limited to those soluble in the acetic acid solvent. The method is not applicable to insoluble peroxides, which exceed 20 carbon atoms.