林产化学与工业2015，Vol.35Issue(6)：119-125,7.DOI:10.3969/j.issn.0253-2417.2015.06.020
热分析法研究冬凌草甲素的热稳定性和分解动力学
Thermal Stability and Decomposition Kinetics of Oridonin by Thermal Analysis Method
刘建群 1高俊博 1刘小红1
作者信息
- 1. 江西中医药大学 现代中药制剂教育部重点实验室,江西 南昌 330004
- 折叠
摘要
Abstract
Thermal decomposing curves of oridonin at different heating speeds were obtained in the nitrogen atmosphere by TG-DTG and DTA-DDTA techniques to study the thermal stability,decomposition kinetics,and shelflife of oridonin under the heat condition. Four thermal analysis kinetic methods ( Kissinger, Ozawa, Coats-Redfern and Achar ) were used to speculate the probable mechanism of thermal decomposing reaction and the kinetic parameters including activation energy Ea and pre-exponential factor A. The shelflife of oridonin at room temperature ( 25℃) was calculated by the kinetic parameters of the first stage. With the increase of the heating rate, thermal decomposing tempreture of oridonin rose. The TG curve showed the decomposition of oridonin could be divided into two steps. The first weight loss rate was 84. 8% from 206. 4 ℃ to 493. 0 ℃ and the second weight loss rate was 15. 2% from 493. 0 ℃ to 669. 6 ℃. The DTA and DDTA curves showed an endothermic peak at about 249℃ and an exothermic peak at about 675℃. The most probable kinetic mechanisms of the first stage thermal decomposition were three-dimensional diffusion and the corresponding mechanisms followed Zhuralev-Lesokin-Tempelman Equation. The average apparent activation energy ( Ea ) was 145. 95 kJ/mol and the pre-exponential factor ( A ) was 4. 87 × 1010 min-1 . The theoretical shelflife of oridonin at room temperature was about 4-5 years.关键词
冬凌草甲素/热分析/热分解动力学Key words
oridonin/thermal analysis/thermal decomposition kinetics分类
化学化工引用本文复制引用
刘建群,高俊博,刘小红..热分析法研究冬凌草甲素的热稳定性和分解动力学[J].林产化学与工业,2015,35(6):119-125,7.
