微米方解石热分解反应的主导曲线

Master Curve of Thermal Decomposition Reactions of Microcrystalline Calcite Particles

针对微米方解石的热分解反应探讨主导曲线模型(MCM)的适用性.利用热重分析仪TGA以获得数组不同升温过程下微米方解石粉体的热重分析数据,包括温度、时间与散失重量,成功地以MCM分析这些反应数据,并拟合得到一条S型主导曲线.采用MCM与传统Avrami Equation两种不同的动力学方法分别求得微米方解石粉体的热分解反应视活化能,MCM所求得的视活化能为219.0kJ/mol,与由Avrami Equation所得到的视活化能208.1kJ/mol相当接近.研究结果表明,主导曲线模型符合理论的预测,可以适用于微米级方解石颗粒的热分解反应,不仅可以预测各种反应过程,也可以求取其视活化能.

As a potentially universal kinetics model,the applicability of Master Curve Model(MCM) on thermal decomposition of microcrystalline calcite particles was investigated in this study.A sigmoidal master curve was successfully derived from TGA data by MCM.The activation energies of the thermal decomposition reactions were also derived by both MCM and Avrami Equation.The activation energy calculated by MCM is 219.0 kJ/mol,which is very close to the one derived from Avrami Equation,i.e.,208.1 kJ/mol.The study shows that MCM not only can be used to analyze and predict the thermal decomposition reactions of micron-sized calcite,but also to calculate the activation energy as well.