Isoconversional analysis on the non-isothermal decomposition kinetics of high energy oxidizer: Potassium dinitramide (KDN)

•Decomposition kinetics of potassium dinitramide studied by isoconversional methods.•Dependence of activation energy (Ea) on conversion shows a multi-step kinetics.•The conversion vs. time was predicted using an integral isoconversional method.•A mechanistic approach was proposed for elucidating the decomposition mechanism of KDN. The thermal decomposition kinetics of an energetic oxidizer viz., potassium dinitramide (KDN) has been studied by non-isothermal thermogravimetry (TG) technique. The dependence of activation energy (Ea) on conversion (α) was evaluated using isoconversional method of Vyazovkin (VYZ). A strong dependence of Ea on α was observed, where the mean Ea value of 185.86 kJ/mol was obtained from VYZ. The classical Kissinger method has also been used to calculate the Ea for the decomposition of KDN. Isothermal conversion-time data was predicted from the kinetic parameters derived from the integral isoconversional method of Vyazovkin. The preexponential factor was calculated by a model-free estimate using the kinetic compensation effect. A mechanistic approach for the decomposition of KDN is proposed based on TG-MS studies, Raman spectroscopy and quantitative analysis of the decomposition products.