Theoretical investigation of thermogravimetric analysis on the decomposition of solid-state materials

Abstract

Thermogravimetric (TG) analysis and differential thermogravimetric (DTG) analysis are the most commonly used analytical techniques to determine the kinetic behaviour of solid-state chemical reactions through Arrhenius parameters and reaction model, which is called the kinetic triplet of solid-state reactions. There are number of methods proposed in the literature for extracting the kinetic parameters of solid-state reactions from TG & DTG thermograms. However, thermal event separation using curve fitting where overlapped thermal events may be present is mandatory before further TG/DTG analysis. In this study, a better curve fitting procedure and a new model fitting method for kinetic parameter extraction is proposed. Enhanced accuracy of the proposed method is proved by MATLAB® based, simulated DTG signals. Furthermore, a mathematical approach using higher differentials of DTG signal was developed to count the number of thermal events in overlapped DTG peaks.