Kinetics of gum rosin oxidation under 365 nm ultraviolet irradiation

• DOI: 10.1007/s00706-013-1014-7
• Publication Date: 2013-06-06T09:19:14Z
• Authors: Jia-Ling Liu; Xiong-Min Liu; Wei-Guang Li; Li Ma; Fang Shen
• Keywords: Ultraviolet; Ultraviolet light; Quantum yield; Light intensity; Linear relationship

The oxidation of gum rosin was performed on a continuous-experiment apparatus under 365 nm ultraviolet (UV) irradiation. The kinetic constant for the oxidation of gum rosin was determined by UV spectrophotometry. The effects of different temperatures and light intensities on the oxidation rate constant were investigated. The results obtained and conclusions drawn were as follows. First, the oxidation of gum rosin is an apparent first-order reaction under 365 nm ultraviolet irradiation. Second, the light intensity significantly affects the oxidation rate constant. There is no obvious influence of temperature. Third, at different temperatures, the relationship between the rate constant and light intensity is linear under 365-nm ultraviolet (UV) irradiation, and linear regression equations were subsequently obtained. Lastly, the initial quantum yield does not vary with light intensity. At 35 °C, the average quantum yield was 0.3318.