Kinetics of thermal decomposition of 4,4′-azobis-(4-cyanopentanoic acid) and its salts in aqueous solution

Abstract

The thermal decomposition of 4,4′-azobis-(4-cyanopentanoic acid)(I) and its salts in aqueous solution has been found always to follow first-order kinetics under a variety of conditions. The rate of decomposition is strongly temperature dependent, with an activation energy of 132.9 ± 1.1 kJ mol^–1. The frequency factor is 6.21 × 10¹⁵ s^–1. The rate of decomposition varies little with changes in either ionic strength or pH. Salts of (I) formed with various monovalent cations decompose at similar rates, as does the free acid. The rate of decomposition may be enhanced by the presence of organic compounds.