Thermal Decomposition And Anti-hygroscopicity Study Of Ammonium Dinitramide

Ammonium dinitramide is a new oxidizer with high energy. It is considered as a potential replacement for ammonium perchlorate in propellant applications because of its properties of relatively high density, high oxygen content, and an acceptable heat of formation, while avoiding the chlorine-containing combustional gas.Thermal decomposition of ADN has been studied by DSC and TG. The influence of heating rate, N₂ gas flow rate, water content, AUN content and AN content on the thermal decomposition process of ADN are studied. The activation energy curves of ADN during its' thermal decomposition process are obtained by the model-free isoconversional method. Several kinds of stabilizeres which can improve apparently the thermal stability of ADN are gotten by experimental study.The mechanism and the effect of burning catalyst in propellant, such as salts of copper, iron, calcium and ammonium, on the decomposition of ADN are studied.The hygroscopicity of ADN at different temperature, relative humidity and adsorption time are determined in this paper. The concept of theoretical saturated hygroscopicity of ADN is put forward and the values of the theoretical saturated hygroscopicity of ADN and the corresponding adsorption time are calculated. The mechanism of the hygroscopicity of ADN is analysied. The anti- hygroscopicity study is carried out and the results show that the hygroscopicity of ADN can be reduced to 75-85% when it is coated with octadecanoly amine or paraffin.The compatibility of ADN and normal component of propellant has been studied by DSC and TG. The results show that the ADN has good compatibility with majority components.