异丙醇铝水解缩聚动力学

Kinetic Analysis of Aluminum Isopropoxide Hydrolysis-Condensation

利用水含量在线测定实验与计算机模拟相结合的方法研究了异丙醇铝水解-缩聚动力学。通过对不同异丙醇铝和水物质的量之比和不同温度下反应获得的水含量随时间变化曲线进行分析,采用非线性拟合方法分别求得异丙醇铝水解、脱水和脱醇缩聚的反应速率常数及活化能。利用实验结果及建立动力学模型,由龙格库塔法计算异丙醇铝的水解缩聚过程,并求得不同反应温度和初始反应物浓度比条件下各官能团浓度与反应终止时间的关系,进而获得反应终止时间与反应温度、初始反应物异丙醇铝浓度、异丙醇铝和水物质的量之比之间的关系方程,为制备低成本高纯氧化铝提供有价值的参考。

Aluminum isopropoxide hydrolysis-condensation kinetics was studied by method of combining the experiment of water content on-line determination with computer simulation.The rate constants and activation energy of hydrolysis,dehydration and dealcoholization of aluminum isopropanol were obtained respectively by nonlinear fitting method of the curve of water content via time which based on different Al(OR)3/H2O mole ratio and different temperatures.Based on the experimental results and the established kinetic model,the relationship between the concentration of functional groups and the reaction termination time under different reaction temperatures and initial reactants concentration ratios was obtained by Runge-Kutta method.Thus,the equation of reaction time,reaction temperature,and concentration of aluminum isopropanol and molar ratio of aluminum isopropanol to water were obtained.The results provided a valuable reference for preparation of high purity alumina.