2-Dimethylaminoethylazide

Formation and reactions

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

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 (IRFNA) systems have demonstrated longer ignition delays than monomethylhydrazine-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.

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 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

References

1. Mellor, B.. (2004). "A Preliminary Technical Review of DMAZ: A Low-Toxicity Hypergolic Fuel".
2. (February 23, 2000). "Army Develops New Fuel". Spacedaily.com.
3. Michael J. McQuaid. (April 2004). "The Structure of Secondary 2-Azidoethanamines: A Hypergolic Fuel vs. a Nonhypergolic Fuel". Army Research Laboratory.
4. (May 8, 2017). "Theory investigation progress of DMAZ". AIP Conference Proceedings.
5. Zhang, Peng. (2015-01-01). "Density functional theory study of the reactions of 2-azido-N,N-dimethylethanamine with nitric acid and nitrogen dioxide". Combustion and Flame.
6. McQuaid, Michael. (December 2003). "Computationally Based Measures of Amine Azide Basicity and Their Correlation With Hypergolic Ignition Delays". Army Research Laboratory.
7. McQuaid, Michael. (September 2002). "Computational Characterization of 2-Azidocycloalkanamines: Notional Variations on the Hypergol 2-Azido-N,N-Dimethylethanamine (DMAZ)". Army Research Laboratory.
8. (January 2014). "A Thermochemical Kinetic-Based Study of Ignition Delays for 2-Azidoethanamine-Red Fuming Nitric Acid Systems: 2 Azido-N-Methylethanamine (MMAZ) Vs. 2 Azido-N,N-Dimethylethanamine (DMAZ)". Army Research Laboratory.