基于热分析的亚油酸甲酯热解动力学研究

摘要

Thermo-decomposition characteristics of methyl linoleate were investigated using a thermo-gravimetric analyzer under nitrogen and oxygen atmospheres, respectively. The decomposition kinetics of methyl linoleate was analyzed by Coats-Redfern integral method. The kinetic models and parameters for thermo-decomposition of methyl linoleate were built and calculated. The results indicate that thermo-decomposition of methyl linoleate under nitrogen or oxygen atmosphere is a two-step process, and methyl linoleate exhibits relatively worse thermo-stability under oxygen atmosphere. Moreover, the decomposition temperature of methyl linoleate increases with the increase of heating rates. The decomposition activation energy and the pre-exponential factor present good kinetic compensation effects, and the kinetic mechanism functions are different under different heating rates. Furthermore, statistical analysis also show that the relative error of the decomposition rate between calculated and experimental values is about 10%, which demonstrates that the kinetic models are reliable and effective in predicting thermo-decomposition processes of methyl linoleate.%采用热重分析方法研究了亚油酸甲酯在氮气和氧气气氛中的热分解特性，并采用Coats-Redfern积分法对亚油酸甲酯的热解过程进行动力学分析，建立了热分解动力学模型，计算了相应的动力学参数。结果表明，亚油酸甲酯在两种气氛中的热分解均为两步分解过程，且在氧气气氛中的热安定性较差。随着升温速率提高，热解区间向高温区移动，热解活化能和指前因子呈较好的动力学补偿效应，且在不同升温速率下具有不同的热解反应机理函数。热分解率计算值与实测值的误差统计分析结果表明，数值模拟计算值与实测值的误差在10%左右，动力学模型可有效预测亚油酸甲酯的热分解过程。