Derivation of Rate Equations used in Thermogravimetry

Abstract

THERE have been many attempts to extract kinetic parameters, such as energy of activation or order of reaction, from dynamic thermogravimetric data^1–3. The main reasons for using thermogravimetry (TG) instead of the more traditional isothermal methods are that it is unnecessary to know the time and temperature of the onset of decomposition, and with TG it is possible to use only one set of experimental data to derive the desired parameters. In other methods, several isothermal experiments must be performed at different temperatures to yield a value for the energy of activation. It should be noted, however, that some of the best TG methods (Friedman⁴ and Osawa⁵) entail several experiments at different heating rates.