Evaluation of reliability of Coats-Reffern method for kinetic analysis of non-isothermal TGA
Evaluation of reliability of Coats-Reffern method for kinetic analysis of non-isothermal TGA
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DOI：
10.1016/s1003-6326(08)60039-4
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发表时间：
2008-02-01
影响因子：
4.5
通讯作者：
Abbasi, M. H.
中科院分区：
文献类型：
--
作者：
Ebrahimi-Kahrizsangi, R.;Abbasi, M. H.
利用广泛应用的Coats-Redfern(CR)方程对非等温热分析速率测量动力学参数的可靠性进行了严格检验。为此，对不同动力学模型的反应进行了模拟 TGA 曲线，包括不同加热速率下的化学、扩散 (Janders) 和混合机制。结果表明，对于由一种机理动力学控制的反应，利用CR方法，所有固态反应模型都呈现线性趋势，并且该方法不能区分正确的反应模型。对于混合机理的反应，CR方法表现出非线性趋势，无法从CR曲线中提取反应模型和动力学参数。对 TGA 数据动力学分析 CR 方法特征的比较评估得出的总体结论是 CR 方法通常不适用于动力学参数的确定。
A critical examination was made on the reliability of kinetic parameters of nonisothermal thermoanalytical rate measurement by the widely applied Coats-Redfern(CR) equation. For this purpose, simulated TGA curves were made for reactions with different kinetic models, including chemical, diffusion (Janders) and mixed mechanism at different heating rates. The results show that, for reactions controlled kinetically by one mechanism, all solid state reaction models show linear trends by use of CR method and this method can not distinct the correct reaction model. For reactions with mixed mechanism, the CR method shows nonlinear trends and the reaction models and kinetic parameters can not be extracted from CR curves. The overall conclusion from this comparative appraisal of the characteristics of the CR approach to kinetic analysis of TGA data is that the CR approach is generally unsuitable for determination of kinetic parameters.