School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China.
Molecules. 2018 Oct 30;23(11):2816. doi: 10.3390/molecules23112816.
A self-designed reaction device was used as a promising equipment to investigate the oxidation characteristics and kinetics of rosin pentaerythritol ester (RPE) under UV irradiation. Photo-oxidation kinetics and the initial quantum yield (Φ) of RPE were calculated. The initial oxidation product of the photo-oxidation reaction-peroxide was analyzed by iodimetry. The peroxide concentration is related to the light intensity (I) and the temperature (T), and the increasing T and I would destabilize the RPE by accelerating peroxide forming. Photo-oxidation of RPE follows the pseudo first-order reaction kinetics. The relationship between activation energy and logarithm of light intensity (ln I) is linear, and it is expressed as Ea = -4.937ln I + 45.565. Φ was calculated by the photo-oxidation kinetics, and the average value of Φ was 7.19% in the light intensity range of 200⁻800 μW cm. This research can provide fundamental information for application of RPE, and help obtain a better understanding of the stability of rosin esters.
采用自行设计的反应装置作为一种有前途的设备，研究了松香季戊四醇酯（RPE）在紫外光照射下的氧化特性和动力学。计算了光氧化动力学和 RPE 的初始量子产率（Φ）。通过碘量法分析光氧化反应的初始氧化产物-过氧化物。过氧化物浓度与光强（I）和温度（T）有关，增加 T 和 I 会通过加速过氧化物形成而使 RPE 不稳定。RPE 的光氧化反应遵循准一级反应动力学。活化能与光强对数（ln I）之间的关系是线性的，可以表示为 Ea = -4.937ln I + 45.565。通过光氧化动力学计算出 Φ，在 200⁻800 μW cm 的光强范围内，Φ 的平均值为 7.19%。这项研究可为 RPE 的应用提供基础信息，并有助于更好地理解松香酯的稳定性。
