Thermal inertias and confidence intervals in the determination of activation energy by isoconversional methods applied for accelerating rate calorimetry

Abstract

Isoconversional method has been preliminarily applied in accelerating rate calorimetry (ARC) and achieved good results. However, it is a new subject and needs to be explored in depth. In this study, the Friedman and the Vyazovkin methods were applied to investigate the influences of thermal inertia on the activation energy estimation of the single-step reaction and autocatalytic reaction. The accuracy and adaptability of the two kinetic methods are compared, and the confidence intervals for activation energy estimated by the Friedman and the Vyazovkin methods are evaluated based on the corrected Student's distribution and F distribution. Finally, the validity of the simulation result is verified by the experiments. The results show that the sets of thermal inertia have different effects on the estimation of activation energy in single-step reaction and multi-step reaction, and the activation energies in multi-step reaction change obviously under different sets of thermal inertia. The thermal inertia increment of 0.03-0.5 and the Vyazovkin method are recommended. This study is helpful to promote the development of isoconversional methods applied for ARC data.