Investigation of the catalytic effect of nano ferrite CoCuNiFe2O4 on the thermal decomposition behavior of ammonium nitrate

Abstract

Ammonium nitrate (AN) is a high energetic material that is being explored as a more eco-friendly replacement for ammonium perchlorate (AP) in composite solid propellants. The thermal decomposition properties of AN can greatly influence the thermal and combustion performance of high energetic formulations. To improve the thermal decomposition of AN, nanocrystalline (17.5 nm) cobalt–copper–nickel ferrite (CoCuNiFe₂O₄) was incorporated into AN using physical mixing. The thermal decompositions of pristine AN and AN + CoCuNiFe₂O₄ were compared to evaluate the better-performing energetic formulation. Simultaneous thermal analysis (thermogravimetry (TG)-differential scanning calorimetry (DSC)) was used to obtain information about the thermal decomposition properties of the AN + CoCuNiFe₂O₄ formulation. Decomposition of AN + CoCuNiFe₂O₄ occurred at a 10 °C lower temperature than that of pristine AN. Non-isothermal isoconversion methods were used to calculate the activation energy and pre-exponential factor of the thermal decomposition process using simultaneous thermal analysis data at 5, 10, and 15 °C min⁻¹ heating rates. The non-isothermal isoconversion analysis suggested a lower activation energy barrier of AN + CoCuNiFe₂O₄ (4% decrement than pure AN) with a decreased pre-exponential factor. The thermo-kinetic investigations suggested that AN + CoCuNiFe₂O₄ can be used as a potential energetic ingredient in solid composite formulations for better thermal performance.