Dimethylhydrazine UDMH

Among the homologues of hydrazine, asymmetric dimethylhydrazine (CH3)2N- NH2 is important. It is obtained from dimethylamine by nitrosation followed by reduction 

Under the name of Dimazine or the abbreviation of UDMH it is used for hypergols by mixing with nitric acid. It may also be used with liquid oxygen. 

In the U.S.A. it is employed in Nike Ajax , Rascal and Vanguard rockets (Warren [53]). 

When V2 rockets were first used a mixture of liquid oxygen with 70% methyl alcohol was employed as a fuel. This mixture, however, is not capable of self-ignition, and it had to be ignited by means of a pyrotechnical mixture giving a hot flame. 

Mixtures containing liquid oxygen are less commonly used now for jet propulsion than mixtures with nitric acid. Nevertheless, for obvious reasons, they have much prospect of success considering that liquid oxygen is a 100% oxidant. 

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Hydraziae is toxic and readily absorbed by oral, dermal, or inhalation routes of exposure. Contact with hydraziae irritates the skin, eyes, and respiratory tract. Liquid splashed iato the eyes may cause permanent damage to the cornea. At high doses it can cause convulsions, but even low doses may result ia ceatral aervous system depressioa. Death from acute exposure results from coavulsioas, respiratory arrest, and cardiovascular coUapse. Repeated exposure may affect the lungs, Hver, and kidneys. Of the hydraziae derivatives studied, 1,1-dimethylhydrazine (UDMH) appears to be the least hepatotoxic monomethyl-hydrazine (MMH) seems to be more toxic to the kidneys. Evidence is limited as to the effect of hydraziae oa reproductioa and/or development however, animal studies demonstrate that only doses that produce toxicity ia pregaant rats result ia embryotoxicity (164). 

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]. 

ATSDR (Agency for Toxic Substances and Disease Registry). 1994. Toxicological Profile for Hydrazine. Draft. U.S. Department of Health and Human Services, ATSDR, Atlanta, Ga. Back, K.C., M.K.Pinkerton, A.B.Cooper, and others. 1963. Absorption, distribution, and excretion of 1,1-dimethylhydrazine (UDMH). Toxicol. Appl. Pharmacol. 5 401—413. 

Haun, C.C. 1977. Canine hepatotoxic response to the inhalation of 1,1-dimethylhydrazine (UDMH) and 1,1-dimethylhydrazine with dimethylnitrosamine (DMNA). 

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],... 

Dimethylhydrazine and derivs 5 D1344—D1346 sym-dimethylhydrazine 5 D1346 uns-dimethylhydrazine (UDMH)... 

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). 

Dimethylhydrazine and Derivatives uns-Dimethylhydrazine (UDMH) (1,1-Di-methylhydrazine), code name Dimazine, (H3O2N.NH2 mw 60.10, N 46.62% col flammable liq with ammonia-like odor hygroscopic sp gt 0.791 at 22° ft p minus 58° bp 63° v sol in w, ale, eth in hydrocarbons. Following methods of prepn are listed in Refs 1 11 a) reaction of dimethylamine (DMA) chloramine ... 

Back KC, Thomas AA. 1962. Pharmacology and toxicology of 1,1-dimethylhydrazine (UDMH). AMRL-TDR-62-118. 

Emst H, Rittinghausen S, Wahnschaffe U, et al. 1987. Induction of malignant peripheral nerve sheath tumors in European hamsters with 1,1 -dimethylhydrazine (UDMH). Cancer Lett 35 303-311. 

Frazier DE, Tarr MJ, Olsen RG. 1991. The in vitro and in vivo effects of 1,1-dimethylhydrazine (UDMH) on murine Ivmphocvte subsets and IA antigen expression. Immunopharmacol Irnmunotoxicol 13 25-46. 

Reinhardt CF, Dinman BD. 1965b. Toxicity of hydrazine and 1,1-dimethylhydrazine (UDMH) Hepatostructural and enzymatic change. Arch Environ Health 10 859-869. 

Reynolds HH, Rohles FH, Prine JR, et al. 1964. The effect of 1,1-dimethylhydrazine (UDMH) on complex avoidance behavior in the Java monkey. Aerosp Med 377-382. 

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 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... 

Figure 11.15 (a) First mechanism proposed for formation of NDMA by chlorination of water via reaction of chloramines with a dimethylamine to form chlorodimethylamine (CDMA) and thence unsynunetrical dimethylhydrazine (UDMH). (b) Further reactions of UDMH with chloramines to form NDMA plus other identifiable reaction products dimethyldiazene (DMD), tetram-ethyltetrazene (TMT), dimethylcyanamide (DMC), dimethyl-formamide (DMF), formaldehyde dimethylhydrazone (FDMH), formaldehyde monomethylhydrazone (FMMH). Reproduced from Mitch, Env. Sci. TechnoL 36, 588 (2002), copyright (2002) with permission of the American Chemical Society. 

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