Characteristics and kinetics of the glycerol ester of rosin via an oxidation process under ultraviolet irradiation

Abstract

A self-designed mini gas–solid reaction device was applied as promising equipment to investigate the oxidation characteristics and kinetics of the glycerol ester of rosin (GER) under 254 nm UV irradiation in air. Peroxide formation during the photo-oxidation process was analyzed by iodimetry. The peroxide concentration is related to the light intensity (I) and the temperature (T), and increasing I and T would destabilize the GER by accelerating peroxide generation. The photo-oxidation of GER followed pseudo-first-order reaction kinetics under a given hypothesis. A linear relationship was observed between activation energy and the logarithm of light intensity (ln I), which can be expressed as E_a = −3.575 ln I + 34.943 under the experimental conditions. This research indicated that under 254 nm UV irradiation GER could be easily oxidized even at room temperature.