MECHANISM AND KINETICS OF DECOMPOSITION OF SOLIDS BY A THERMOGRAVIMETRIC METHOD

According to Doyle, the thermogravimetric curve of a decomposition reaction can be expressed by the equation log g(α)–log p(x) = B. The variable x depends on the temperature Tα, at which the fraction of the initial compound decomposed is α. Both g(α) and p(x) depend on temperature; however, B is independent of temperature. The trial‐and‐error method allows, for a given thermogravimetric curve, the determination of the g(α) and p(x) functions fitting the equation and thus an estimation of the probable mechanism of the reaction and of other kinetic parameters (activation energy and frequency factor). To facilitate the analysis of experimental data, a table of log g(α) values for various decomposition mechanisms and a plot of‐log p(x) vs T for various activation energies are presented. The use of the table and the diagram is described. Copyright © 1969, Wiley Blackwell. All rights reserved