Study of thermal degradation behavior and kinetics of ABS/PC blend

This work investigated kinetics and thermal degradation of acrylonitrile butadiene styrene and polycarbonate (ABS/PC) blend using thermogravimetric analysis in the range of 25 to 520 degrees C. For thermal degradation of blend, activation energy (E-a) and pre-exponential factor (A) were calculated under various heating rates as 5, 10, 15 and 20 degrees C/min using iso-conversional model-free methods (Kissinger, Flynn-Wall- Ozawa and Friedman). Mass loss of the blend as a function of temperature was plotted as thermogravimetric curve (TG) while derivative values of mass loss were drawn as derivative thermogravimetric (DTG) curve. Using Kissinger method, E-a was 51.4 kJ/mol, while values calculated from FWO and Friedman method were 86-161 and 30-251 kJ/mol respectively. Results showed increasing trend of E-a with higher conversion values indicating different degradation mechanisms at the initial and final stages of the experiment. Thermodynamic parameters such as enthalpy change (Delta H), Gibbs free energy (Delta G) and entropy change (Delta S) were also calculated.