盐酸石蒜碱的热降解机理及其分解动力学研究

林产化学与工业 ›› 2012, Vol. 32 ›› Issue (5): 77-82.

盐酸石蒜碱的热降解机理及其分解动力学研究

田春莲, 肖卓炳

吉首大学林产化工工程湖南省重点实验室, 湖南张家界 427000

收稿日期:2012-06-01 修回日期:1900-01-01 出版日期:2012-10-30 发布日期:2012-10-30

Thermal Decomposition Mechanism and Kinetics of Lycorine Hydrochloride

TIAN Chun-lian, XIAO Zhuo-bing

Key Laboratory for Forest Products and Chemical Industry Engineering,Jishou University, Zhangjiajie 427000, China

Received:2012-06-01 Revised:1900-01-01 Online:2012-10-30 Published:2012-10-30

摘要/Abstract

摘要： 利用热重-微分热重技术测得盐酸石蒜碱在氮气气氛中的热分解曲线,协同使用Achar法和Coats-Redfern法两种方法同时进行动力学处理,根据热分解的表观活化能(E_a)和指前因子(A)计算推断石蒜碱的贮存期。盐酸石蒜碱晶体在154.9~233.9 ℃ 失去一分子H₂O和一分子HCl转为石蒜碱,第二步分解(233.9~309.2 ℃)和第三步分解前半部分(α_0.2-0.7,309.2~407.9 ℃)的机理都是化学反应控制,对应的函数名称是反应级数方程,反应级数n=2;第三步分解后半部分(α_0.8-1.0,407.9~467.5 ℃)时为随机成核和随后生长控制机制,符合Avrami-Erofeev方程。经Gaussian模拟和热重数据结合分析,晶体在第二步分解时,失去1分子CO₂;第三步分解分两个阶段完成,首先失去1分子CO₂和1分子NH₃,然后再释放出一分子的CH₄;根据第二步热分解的表观活化能(E_a)和指前因子(A)推断,在室温 25 ℃ 下,石蒜碱的贮存期为 3 a。

关键词: 盐酸石蒜碱, 石蒜碱, 热分析动力学, Gaussian模拟

Abstract: Thermal decomposing curves of lycorine hydrochloride were obtained in the nitrogen atmosphere by thermogravimetry and differential thermogravimetry techniques. Two thermal analysis kinetic methods of Achar and Coats-Redfern were used to speculate the probable mechanism of thermal decomposing reaction and the kinetic parameters. The shelflife of lycorine at room temperature was calculated by the kinetic parameters of the thermal decomposition. Before 233.9 ℃, one molecule of the crystalline powder had lost 1 molecule H₂O and 1 molecule HCl. The most probable kinetic mechanisms of the second-stage and third-stage (α_0.2-0.7) thermal decomposition were all chemical reactions. The corresponding mechanisms follow Reaction Order while the third-stage (α_0.8-1.0) thermal decomposition was Nucleation and growth, corresponding with Avrami-Erofeev Equation. In accordance with the data of TG and Gaussian simulation, one molecule of the crystalline powder lost 1 molecule CO₂ at the second-stage weightlessness and lost another 1 molecule CO₂ and 1 molecule NH₃ at α_0.2-0.7 of the third stage while a molecule CH₄ was lost at α_0.8-1.0 of the third stage. The storage time of lycorine at room temperature was about 3 years.

Key words: lycorine hydrochloride, lycorine, thermal analysis kinetics, Gaussian simulation

中图分类号:

田春莲;肖卓炳. 盐酸石蒜碱的热降解机理及其分解动力学研究[J]. 林产化学与工业, 2012, 32(5): 77-82.

TIAN Chun-lian;XIAO Zhuo-bing. Thermal Decomposition Mechanism and Kinetics of Lycorine Hydrochloride[J]. , 2012, 32(5): 77-82.

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