2-Dimethylaminoethylazide (DMAZ) is a liquid

rocket fuel Rocket propellant is the reaction mass of a rocket. This reaction mass is ejected at the highest achievable velocity from a rocket engine to produce thrust. The energy required can either come from the propellants themselves, as with a chemical ...

being investigated for use as a spacecraft propellent to replace the toxic, carcinogenic

monomethylhydrazine Monomethylhydrazine (mono-methyl hydrazine, MMH) is a highly toxic, volatile hydrazine derivative with the chemical formula . It is used as a rocket propellant in bipropellant rocket engines because it is hypergolic with various oxidizers such as ...

. It is a member of the competitive impulse non-carcinogenic

hypergol A hypergolic propellant is a rocket propellant combination used in a rocket engine, whose components spontaneously ignite when they come into contact with each other. The two propellant components usually consist of a fuel and an oxidizer. Th ...

(CINCH) family which were assessed as a replacement for hydrazine-derived propellants. DMAZ was also found to be sensitive to impact, direct flame, shock wave, heat in confined space, and electrostatic discharge.

Formation and reactions

DMAZ is an organic azide, which is prepared by reacting the chloride of the corresponding alkyl-amine (in this case ethylamine) with sodium azide: : Ideally, the complete combustion of DMAZ produces carbon dioxide, water, and nitrogen: :

Ignition delays

During their inquiry into finding alternative hypergolic fuel, a joint effort by the Aviation and Missile Research, Development, and Engineering Center (AMRDEC), the U.S. Army Research Laboratory (ARL), and the National Aeronautics and Space Administration (NASA) determined that DMAZ could perform competitively with Aerozine-50 and is less toxic than hydrazine-based fuels. However, DMAZ-

inhibited red fuming nitric acid Red fuming nitric acid (RFNA) is a storable oxidizer used as a rocket propellant. It consists of 84% nitric acid (), 13% dinitrogen tetroxide and 1–2% water. The color of red fuming nitric acid is due to the dinitrogen tetroxide, which breaks ...

(IRFNA) systems have demonstrated longer ignition delays than

-IRFNA systems. In an effort to address this issue, researchers synthesized the related compounds 2-azidoethanamines – 2-azido-''N''-methylethanamine (MMAZ) and 2-azido-''N''-cyclopropylethanamine (CPAZ) in hopes of enhancing the reactivity of DMAZ's amine nitrogen to reduce ignition delays. MMAZ is not hypergolic, while CPAZ is

hypergolic A hypergolic propellant is a rocket propellant combination used in a rocket engine, whose components spontaneously ignite when they come into contact with each other. The two propellant components usually consist of a fuel and an oxidizer. T ...

. According to research conducted by Army Research Laboratory, the azido group in DMAZ's lowest energy structure will prevent the transfer of protons from nitric acid to the amine lone pair acid, a chemical reaction that may be associated with a

rate-limiting step In chemical kinetics, the overall rate of a reaction is often approximately determined by the slowest step, known as the rate-determining step (RDS or RD-step or r/d step) or rate-limiting step. For a given reaction mechanism, the prediction of th ...

in DMAZ-IRFNA ignition. However, according to a 2014 ARL report, a correlation between compound basicities and ignition delays was not observed, which indicates that the proton transfer from nitric acid to DMAZ's amine may not be a rate-controlling step in the ignition process of DMAZ-IRFNA systems.

References

{{DEFAULTSORT:Dimethylaminoethylazide, 2- Rocket fuels Organoazides Dimethylamino compounds