PREPARATION AND USE OF AMMONIUM AND SODIUM AZIDE AS A FUEL ADDITIVE TO IONIC OXIDIZER

摘要

Ammonium azide (AA, NH{sub}4N{sub}3) has been prepared from sodium azide (SA, NaN{sub}3) through an ion-exchange procedure using cationic resins. The control of the resulting solution has been obtained by acid-base titration, and the exchange efficiency is higher than 90%. The aqueous binary azide-water solutions and the ternary stoichiometric azide-HAN-water mixtures have been prepared and investigated for thermal and catalytic decomposition using a thermal analysis apparatus and a constant volume batch reactor. The experiments show the dilution influence on ammonium azide decomposition. The presence of the oxidizer (HAN: NH{sub}3OHNO{sub}3) leads to an acido-basic reaction between hydroxylammonium cation (NH{sub}3OH{sup}+) and azide ion (N{sub}3), thus favoring the endothermic vaporization of a part of azide at low temperature, whereas the thermal decomposition of pure sodium azide shows too exothermic peaks at 411°C and 492°C. The latter is being due to the liquid sodium recombination with the gas vector impurities (O{sub}2 and H{sub}2O vapour).