Non-isothermal kinetics of thermal degradation of chitin

Thermogravimetric studies of chitin in air atmosphere were carried out at six rates of linear increase of the temperature. The kinetics and mechanism of the thermal decomposition reaction were evaluated from the TG data by iso-conversional calculation procedure of Kissinger-Akahira-Sunose recommended from ICTAC kinetics committee, as well as 27 mechanism functions. The comparison of the results obtained showed that they strongly depend on the selection of proper mechanism function for the process. Therefore, it is very important to determine the most probable mechanism function. In this respect, the iso-conversion calculation procedure turned out to be the most appropriate one. In the present work, the values of the apparent activation energy E, pre-exponential factor A in Arrhenius equation, as well as the changes of entropy Delta S (not equal), enthalpy Delta H (not equal), and Gibbs free energy Delta G (not equal) for the formation of the activated complex from the reagent are calculated. All the calculations were performed using programs compiled by ourselves.