Description of the shape of thermoanalytical curves : Part 3. A Method for estimating kinetic constants from parameters characterizing peak shape

The relationships between empirical parameters characterizing the shape of thermo-analytical curves and the constants of the kinetic equation, dα/dt = A exp (?E/RT)(1 ? α)ⁿ, are studied. A procedure is developed for the estimation of the three constants of this equation from the empirical parameters. The efficiency of this method is compared to that of model fitting. In evaluation of the confidence intervals of estimated constants and in the case of identification, least-squares (or similar) fitting is shown to be inferior because of its low sensitivity to properties other than the position of the peak along the temperature axis. This lack of sensitivity may be a major cause of the apparent kinetic compensation effect often encountered in the field of thermal analysis.