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The thermal degradation of chitosan–cobalt complex at different heating rates in nitrogen was studied by thermogravimetric analysis (TGA) in the temperature range 30–800 °C. Fourier transform-infrared (FTIR) and X-ray diffractogram (XRD) analyses were utilized to determine the micro-structure of chitosan–cobalt complex. The results indicate that the thermal degradation of chitosan–cobalt complex in nitrogen is a two-step reaction, characteristic temperatures and the maximum reaction rate of thermal degradation increase with the increment of heating rate. The kinetic parameters were determined by using Friedman and Flynn–Wall–Ozawa methods. Coats–Redfern method was used to discuss the probable degradation mechanism. The results show that activation energy of the complex resulting from two kinetic methods has similar variable tendency, and the solid-state decomposition in the first degradation stage, which is non-spontaneous, goes to a mechanism involving nucleation and growth, Avrami–Erofeev function ( A 4 ) with integral form [−ln(1 − α )] 4 .

The thermal degradation of quaternized chitosan–cupric ion compounds in nitrogen was studied by thermogravimetry analysis (TG) and differential thermal analysis (DTA). The effect of cupric ions on the thermal degradation behaviors of quaternized chitosan was discussed. Fourier transform-infrared (FTIR) and X-ray diffraction (XRD) were utilized to determine the micro-structure of quaternized chitosan–cupric ion compounds. The results of FTIR and XRD show that there are coordinating bonds between quaternized chitosan and cupric ions. Thermal analysis indicates that the thermal degradation of quaternary chitosan–cupric ion compounds is a two-stage reaction, in which there are the decomposition of N–C2 bond on the side-chain of quaternized chitosan and the cleavage of glycosidic linkages of chitosan. The two reactions are exothermic. The impact of cupric ion on the thermal degradation of quaternized chitosan is significant, and the temperature and activation energy of the degradation are related to the weight fraction of the cupric ion.