基于非等温热重法的氟化石墨热分解动力学研究

针对氟化石墨热分解动力学机理不确定和动力学预测信息不足的问题，通过测量多组非等温热重曲线，并利用无模型动力学方法分析（CF）_n热分解反应动力学机理.热重曲线显示（CF）_n热分解经历一步失重，产生的平均气相成分为CF_2.95.动力学分析结果表明机理函数随转化率依次变化:α < 0.1，机理函数为JMA方程f（α）=1.5（1-α）-ln（1-α）]1/3；0.15 < α < 0.3，机理函数为二维Avrami-Erofeyev方程f（α）=2（1-α）-ln（1-α）]1/2；0.3 < α < 0.8，机理函数为?esták-Berggren方程f（α）=7.5α1.2·（1-α）2；0.85 < α，机理函数为一维Avrami-Erofeyev方程f（α）=（1-α）.推荐的动力学预测参量活化能为264.23±7.82 kJ/mol，指前因子为（8.70±0.21）×1014/s.另外，动力学机理反映出（CF）_n分解过程存在碳核的链生长以及与分支链的相互作用的特征，这可能是反应产物形成非晶态结构碳的重要因素. 

On the thermal decomposition kinetics of graphite fluoride based on non-isothermal thermogravimetry

Aiming at the problem of uncertain mechanism of kinetics of thermal decomposition of fluorinated graphite and insufficient information of kinetic prediction, the dynamic mechanism of (CF)_n thermal decomposition reaction was analyzed by measuring multiple sets of non-isothermal thermogravimetric curves and using model-free kinetics. The thermogravimetric curve shows that (CF)_n thermal decomposition undergoes one step of weight loss, resulting in an average gas phase composition of CF_2.95. The results of kinetic analysis show that the mechanism function changes with the conversion rate: α < 0.1, the mechanism function is JMA equation f(α)=1.5(1-α)-ln(1-α)]1/3; 0.15 < α < 0.3, the mechanism function is two-dimensional Avrami-Erofeyev equation f(α)=2(1-α)-ln(1-α)]1/2;0.3 < α < 0.8, the mechanism function is ?esták-Berggren equation f(α)=7.5α1.2(1-α)2; 0.85 < α, the mechanism function is the one-dimensional Avrami-Erofeyev equation f(α)=(1-α). The recommended kinetic prediction parameter activation energy is 264.23±7.82 kJ/mol, and the pre-exponential factor is (8.70±0.21)×1014/s. In addition, the kinetic mechanism reflects the existence of carbon chain chain growth and interaction with the branching chain in the (CF)_n decomposition process, which may be an important factor in the formation of amorphous structural carbon in the reaction product.