C_8H_4O_5Na_2·H_2O脱水过程的热分析动力学研究

Kinetics of dehydration decomposition of C_8H_4O_5NNa_2·H_2O in non-isothermal conditions

为了获得一水合5-羟基间苯二甲酸钠(C8H4O5Na2.H2O)固态样品脱水过程的动力学三因子(反应级数n、表观活化能Ea、指前因子A)及相应的动力学方程,应用DSC技术获得化合物4个不同升温速率下的脱水过程曲线,利用多重扫描速率法,以"非模型等转化率法"为基础,采用9种积分法和微分法相结合的热分析动力学方法处理程序进行定量表征.结果显示C8H4O5Na2.H2O脱水阶段的反应为化学反应机理,表观活化能Ea为183.07kJ.mol-1,指前因子A为3.02×1018s-1,动力学方程为(dα/dT)=(3.02×1018)/β(1-α)2exp(-2.202×104/T).

To obtain the kinetic parameters （reaction order n, the apparent activation energy Ea, the pre-exponential factor A） and the most probable kinetic model function of the dehydration decomposition of solid compound C8H4O5Na2·H2O. From an analysis of the DSC curves at four different heating rates by integral and differential methods based on model-free isoconversional methods. The most probable kinetic model function of the dehydration decomposition reaction is chemical reaction, and the apparent activation energy Ea is 183.07 kJ·mol^-1 , the pre-exponential factor A is 3. 02 ×10^18s^-1, the kinetic equation is dα/dT=3.02×10^18/β（1-α）^2exp（-2.202×10^4/T）.