Degradation Kinetics of Polycarbonate in Supercritical Methanol

A kinetic analysis method using the nonisothermal weight loss technique is proposed to conveniently determine the kinetic parameters of degradation of polycarbonate (PC) in supercritical methanol. Experiments have been carried out for three heating rates of 8, 10.5 and 13 degrees C/min. The slope of a straight line plot for a function of the weight fraction vs. the temperature gives the activation energy of PC degradation in supercritical methanol. In addition, the weight fraction at which the inflection occurs in the weight loss curve determines the reaction order. From this work, it has been found that the activation energies of PC degradation in supercritical methanol are 386.5-501.9 kJ/mol. Further, it has also been found that the reaction orders are 1.79-2.89 and there are variations in the calculated kinetic parameters depending on the heating rate.