Unsymmetrical dimethylhydrazine UDMH

Until recently the atmospheric chemistry of nitrogen-containing compounds such as the hydrazines, which are widely used as fuels in military and space vehicles, has received comparatively little attention. N,N-dimethyIhydrazine (also UDMH = unsymmetrical dimethylhydrazine) is used in liquid-fueled rockets, and thus there Is a possibility that its use, storage, and handling could result in its release in the atmosphere. 

Synonyms/Trade Names Dimazine, DMH, UDMH, Unsymmetrical dimethylhydrazine... 

The determination of organic compounds by their direct catalytic effect on indicator reaction rates is a relatively unexplored ai ea promising valuable analytical chai acteristics, as we have recently shown in the determination of traces of unsymmetrical dimethylhydrazine (UDMH) by the oxidation of 3,3, 5,5 -tetramethylbenzidine (TMB) by atmospheric oxygen initiated with persulfate [1]. 

Of the many alkyl substituted hydrazines, only two are used as rocket fuels now monomethyl hydrazine (MMH), CH3NHNH2, and unsymmetrical dimethylhydrazine (UDMH), (CH3)2NNH2. (See Hypergolic Fuels in this Vol for combustion properties as rocket fuels). Their physical properties are summarized below... 

They remain liquid under normal, ambient operating conditions (moderate temperature, atmospheric pressure). Safety in storage and handling should also be considered. A storable liquid propellant should not have an excessively high vapour pressure at ambient temperature. The leading storable propellant uses dinitrogen tetroxide as oxidizer and a 50/50 mixture of hydrazine-unsymmetrical dimethylhydrazine (UDMH) as fuel [71], Nitrogen tetroxide and UDMH is another storable propellant mixture in use [73],... 

Storable. Together with liquid hydrocarbons, hydrazine-type fuels are the most important storable liquid propellants. They include hydrazine (N2H4), MMH, unsymmetrical dimethylhydrazine (UDMH), Aerozine-50 (50% N2H4 and 50% UDMH), and various blends of these fuels with other amine-based components. All hydrazine-type fuels are toxic to some degree, as are their breakdown products in the environment (especially, as in the case of dilute UDMH with nitrates and nitrites, forming carcinogenic and highly water soluble nitrosodimethylamine, or NDMA). The most notable hydrocarbon storable fuels include kerosene-based liquid propellants (RP-1, JP-8, and others). 

Smith EB, Clark DA. 1971. Absorption of unsymmetrical dimethylhydrazine (UDMH) through canine skin. Toxicol Appl Pharmacol 18 649-659. 

In 1989 a controversy arose concerning the chemical daminozide, or Alar , which was sprayed on apple trees to yield redder, firmer, and more shapely apples. Concerns about Alar s safety stemmed from the suspicion that one of its breakdown products, unsymmetrical dimethylhydrazine (UDMH), was carcinogenic. Alar is no longer sold for food uses. UDMH has the empirical formula of CNH4 and has a molecular mass of 60.099. What is the molecular formula for UDMH ... 

SYNONYMS dimazine, N,N-dimethylhydrazine, unsymmetrical dimethylhydrazine, DMH, UDMH. 

Synonyms 1,1-dimethylhydrazine, unsymmetrical- dimethylhydrazine, asymmetrical- dimethylhydrazine UDMH, V,V-dimethylhydrazine, Dimazine 1,2- dimethylhydrazine, symmetrical dimethylhydrazine, SDMH, V,V-dimethylhydrazine Budavari et al. 1989... 

Storables. Hydrazine-type fuels are the most important storable liquid fuels. They include hydrazine (N2H4), monomethyl hydrazine (MMH), unsymmetrical dimethylhydrazine (UDMH), Aerozine-50 (50% N2H4 and 50% UDMH), and various blends of these fuels with other components. All hydrazine-type fuels are toxic to some degree. 

DIMETHYLHYDRAZINE uns-DIMETHYLHYDRAZINE unsym-DIMETHYLHYDRAZINE 1,1-DIMETHYL-HYDRAZINE (GERMAN) DIMETHYLHYDRAZINE, unsymmetrical (DOT) DMH NIESYMETRYCZNA D XTJ METYLOHYDRAZYNA (POLISH) RCRA WASTE NU.MBER U098 UDMH (DOT)... 

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