差热分析法测定5-氟脲嘧啶及其衍生物的分解反应动力学参数

Determination of the thermal decomposition reaction parameters of 5-fluorouracil and its derivatives

目的研究 5 氟脲嘧啶 (5 Fu)、呋喃氟脲嘧啶 (FT 2 0 7)、双呋喃氟脲嘧啶 (FD 1)的热稳定性及其热分解动力学过程和反应动力学参数。方法差热分析 (DTA )法。结果它们的分解反应为一级动力学过程 ,其反应的活化能分别为 2 6 9 382、115 4 39、10 6 4 19kJ·mol-1,频率因子分别为 9 39× 10 18s-1、1 76× 10 8s-1、2 75× 10 7s-1。结论 5 Fu、FT 2 0 7、FD 1的热稳定性顺序为 5 Fu >FT 2 0 7>FD 1。FD 1随着温度的升高首先脱掉一个四氢呋喃降解为FT 2 0 7,继而脱去另一个四氢呋喃降解为 5 Fu。

Objective To study the thermal stability of fluorouracil(5 Fu), ftorafurum(FT 207), tegadifurum(FD 1), their decomposition processes and their reaction parameters.Methods Differential thermal analysis.Results Their reaction order of thermal decomposition was the first.Their activation energy ( E) are 269 382 kJ·mol -1 , 115 439 kJ·mol -1 and 106 419 kJ·mol -1 , respectively.Their frequency factors ( A ) are 9 39×10 18 S -1 ,1 76×10 8S -1 ,2 75×10 7S -1 , respectively.Conclusions The thermal stability order of them is 5 Fu>FT 207>FD 1.With the temperature raised, FD 1 decomposes into FT 207 by putting off a tetrahydrofuran, and then FT 207 decomposes into 5 Fu by putting off another tetrahydrofuran.