Quantitative analyses of HAN-based liquid propellants.

This paper deals with quantitative analyses of HAN-based monopropellants, in particular following stability tests. In the case of the propellant LP 1846, the compounds hydroxylammonium nitrate and triethanolammonium nitrate are determined as the primary compounds, while free nitric acid and ammonium nitrate are considered as decomposition products. As a determination method, potentiometric titration with water as solvent as been selected, using as apparatus a Metrohm "Titroprocessor 636" with a combined glass electrode as an indicator. The propellant components were to be quantified by simultaneous titration in a sample. Therefore, the pK values of the different propellant components have been measured before starting the analytical work. HAN and AN had to be converted to derivates (acetoxim and formaldoxim) to enable the separation of the compounds. As for triethanolammonium nitrate containing propellants such as LP 1846, AN can be titrated after steam destillation due to the nonvolat ility of the free triethanolamine.