交联壳聚糖的合成和非等温热分解动力学

Study on Thermal Degradation Kinetics of Synthetic CCTS

利用 TG- DTG技术研究了合成的 5种交联壳聚糖的热分解历程 .通过对比 Coats- Redfern积分法和Achar微分法对 31种机理函数求得的动力学参数 ,推断出各步的可能热分解反应机理 .5种交联壳聚糖发生第 1步热降解的动力学机理函数相同 ,都为简单三级反应 ,遵循 f (α) =0 .5 (1-α) 3,g(α) =(1-α) - 1 /2 - 1;第 2步均为壳聚糖的分解 ,其热分解的机理函数均为简单的二级反应 ;5种壳聚糖的稳定性为 :CCTS- B- 15 - C- 5 >CCTS>CCTS- 2≈ CCTS- B- 18- C- 6 >CCTS- 1.

In the paper TG-DTG apparatus was used to study on thermal degradation of synthetic CCTS.The kinetics of thermal degradation was investigated by thermogravimetry analysis,the reaction grades and rate constants of thermal degradation were determined.The kinetics mechanism of five CCTS on the first stage are the same, they are third order reactions and followed function f ( α )=0.5(1- α ) 3 and g ( α )=(1- α ) -1/2 -1; thermal degradation was happened on the second stage of five CCTS,they are conformed to second order reactions;thermal stability of five CCTS are CCTS-B-15-C-5>CCTS>CCTS-2≈CCTS-B-18-C-6>CCTS-1.