Determination of Kinetic Parameters for the Degradation of Chitosan/Silica Hybrid Nano Composites

The thermal degradation behavior of chitosan (CS) and chitosan–silica (CS–Si) nanocomposites were studied using a differential kinetic model. The influence of the heating rate in the non-isothermal degradation kinetics of CS and CS–Si nanocomposites are presented. Kinetic parameters, such as the activation energy (E) and pre-exponential factor (A), and thermodynamic parameters, such as the Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS), were determined using the modified Arrhenius equation. It was shown that the rate constant for degradation (k), activation energy and pre-exponential factor depend on the heating rates. The order of reaction was found to be one. The isothermal stability of CS and CS–Si was determined from non-isothermal kinetics and was also found to be dependent on the heating rate. Thermogravimetric studies revealed that neat CS was less thermally stable than the CS–Si nanocomposites.