壳聚糖和甲壳素热分解动力学研究

Kinetic Studies on the Pyrolysis of Chitosan and Chitin

采用多重扫描速率法研究了壳聚糖和甲壳素2种物质的热分解动力学,2种物质的反应活化能E和指前因子lnA分别为(157.81±1.23)、(171.67±3.16)kJ/mol和(26.49±0.26)、(24.20±0.62)min-1。Achar微分法判定了两者的热分解最概然机理函数,壳聚糖的热分解机理函数为f(α)=2(1-α)3/2,属级数反应;甲壳素的分解机理函数为f(α)=3/2(1-α)2/3[1-(1-α)1/3]-1,属三维扩散、球形对称机理。

DSC non isothermal multiple scan curves were applied to investigate the pyrolysis kinetics of chitosan and chitin. The apparent activation energy （E） and frequency factor （lnA） for thermal decomposition were （157.81 ± 1.23 ）, （ 171.67 ± 3.16 ） kJ/mol and （26.49 ± 0.26）, （24.20 ± 0.62 ） min - 1, respectively. And the most probable mechanism functions were obtained by Achar＇ s differential method. The functions of chitosan and chitin were f （f） = 2 （ 1 - α） 3/2 and f（α） = 3/2 （ 1 - α） 2/3 [ 1 - （ 1 - α） 1/3 ] -1, which was considered as 2/3 order chemical reaction and 3D diffusion and ball symmetry mechanism.