Kinetic Studies on the Thermal Dehydration and Degradation of Chitosan and Citralidene Chitosan

Abstract

The thermal dehydration and degradation of chitosan and citralidene chitosan was studied by differential scanning calorimetry at four different heating rates; 5, 10, 15 and 20 K min−1. The kinetics of thermal dehydration and degradation of chitosan and citralidene chitosan was investigated using different isoconversional and maximum rate (peak) methods viz. Kissinger–Akahira–Sunose (KAS), Tang, Starink1.95, Starink1.92, Flynn–Wall–Ozawa (FWO) and Bosewell. The activation energy values of thermal dehydration and degradation reactions obtained from isoconversional methods of FWO and Bosewell are slightly higher than that obtained from other methods. The variation of activation energy, E α with conversion function, α, established using these different methods were found to be similar. Compared to the FWO method, the KAS method offers a significant improvement in the accuracy of the E a values. All the maximum rate (peak) methods yielded consistent values of E α for the dehydration and degradation reactions of both chitosan and CIT-chitosan