壳聚糖-镧复合材料的制备及热分解动力学研究

Preparation and Thermal Decomposition Kinetics of Chitosan- lanthanum Composite Material

以壳聚糖为基体,掺杂稀土元素镧制成复合材料。采用热重分析(TG)技术在不同的升温速率下研究了复合材料在氮气气氛中的热分解过程和非等温热分解机理及动力学。实验表明,该复合材料整个受热过程中表现出两个失重阶段:第一阶段为200~300℃,第二阶段为400~480℃。运用多重速率扫描法中的Ozawa法计算出复合材料两步分解的活化能并与模型法中的微分法(Achar方程)和积分法(Coats-Redfern方程)对非等温动力学数据进行分析得到的两步热分解反应的机理函数和动力学参数进行对比。结果表明,其第一步热分解反应机理为随机成核和随机增长,表观活化能E为131.014 kJ·mol^-1,指前因子A为5.0741×10^9 s^-1;第二步分解反应机理为随机成核和随机增长,表观活化能E为120.347 kJ·mol^-1,指前因子A为4685580 s^-1。

The composite material from chitosan(CS)containing various amount of lanthanum(la)were prepared by blending and freeze-drying method.Thermogravimetric analysis(TG)was used to analysis the thermal decomposition process and non-isothermal thermal decomposition mechanism and kinetics of composites in nitrogen atmosphere at different heating rates.The results showed that the thermal decomposition temperature of chitosan-lanthanum composite material was in the range of 200~480℃.The process divided into two stages,the first stage was 200~300℃and the second stage was 400~480℃.By applying the multiple rate of Ozawa method to calculate the thermal decomposition of the apparent activation energy E and refers to the former factor;At the same time adopted Achar equation and Redferm equation to get the data and analysis the thermal decomposition process.