硝酸胍热分解特性及其动力学分析  

Thermal decomposition characteristics and thermokinetics of guanidine nitrate

作　　者：杨冉 陈东梁[1] 张东胜[1] 何向向 王玉丰 YANG Ran;CHEN DongLiang;ZHANG DongSheng;HE XiangXiang;WANG YuFeng(College of Mechanical and Electrical Engineering,Beijing University of Chemical Technology,Beijing 100029;School of Materials Engineering,Changshu Institute of Technology,Changshu 215500,China)

机构地区：[1]北京化工大学机电工程学院,北京100029 [2]常熟理工学院材料工程学院,常熟215500

出　　处：《北京化工大学学报（自然科学版）》2021年第3期1-8,共8页Journal of Beijing University of Chemical Technology(Natural Science Edition)

基　　金：克拉玛依市重点研发计划项目(2020ZDYF0006)。

摘　　要：采用5、10、15、20 K/min的不同线性升温速率,研究硝酸胍(GN)的热分解过程,通过Flynn-Wall-Ozawa(FWO)法、Kissinger Akahira and Sunose(KAS)法和Coats-Redfern(CR)法进行热动力学分析,并利用热力学理论求解相关热安全性参数。结果表明,硝酸胍在450~700 K的温度范围内呈一步失重,热重法(TG)的平均外推起始温度为580.28 K;当转化率为0.1~0.9时,FWO法和KAS法得到的平均表观活化能分别为140.43 kJ/mol和137.82 kJ/mol,自燃倾向等级为Ⅰ级;CR法表明Avrami-Erofeev(A2)为硝酸胍的最适机理函数模型;在310~370 K的温度范围内,硝酸胍的比热容随温度的升高而逐渐增大,平均值为3.148 J/(g·K);自加速分解温度(T_(SADT))和自发火温度(T_(be0))分别为530-15 K和548-10 K;活化熵(△S^(≠))和活化焓(△H^(≠))随升温速率的增大而减小,活化自由能(△G^(≠))和反应速率常数随升温速率的增大而增大。The thermal decomposition of guanidine nitrate(GN)has been studied at different linear heating rates of 5,10,15 and 20 K/min.The thermokinetics of GN was analysed by the Flynn-Wall-Ozawa(FWO)method,the Kissinger-Akahira-Sunose(KAS)method and the Coats-Redfern(CR)method.The thermal safety parameters were extracted using thermodynamic theory.The results showed that GN displayed a one-step weight loss in the temperature range 450-700 K,and the average extrapolated onset temperature in thermogravimetry(TG)is 580.28 K.The average activation energies obtained using the FWO and KAS methods are 140.43 kJ/mol and 137.82 kJ/mol,respectively,when the conversion rates are 0.1-0.9,and the level of spontaneous combustion tendency is grade Ⅰ.The CR method showed that Avrami-Erofeev(A2)is the optimal mechanistic function model for GN.The specific heat capacity of GN increases gradually with increasing temperature when the temperature is in the range 310-370 K,and the average value is 3.148 J/(g·K).The self-accelerating decomposition temperature(TSADT)and the spontaneous ignition temperature(Tbe0)are 530.15 K and 548.10 K,respectively.The activation entropy(△S^(≠))and activation enthalpy(△H^(≠))decrease as the heating rate increases,while activation free energy(△G^(≠))and reaction rate constant increase as the heating rate increases.

关 键 词：硝酸胍 热分解 热动力学 热安全性参数 

分 类 号：O414.19[理学—理论物理]