2035-89-4Relevant articles and documents
Liquid missile propellants in the former Soviet Union
Fedorov
, p. 157 - 161 (1999)
The liquid missile propellant unsymmetrical dimethylhydrazine (UDMH) is a very toxic and persistent organic chemical that was widely used in the missile industry of the former Soviet Union. Only in the last few years have Russian authorities acknowledged the dangers of this fuel to people and nature. To date, little has been done for the transition towards fuels with a lower toxicity. This paper describes the chemical nature of UDMH, and considers its potential impacts on nature and human health. Copyright (C) 1999 ElsevierScience Ltd. All rights reserved.
Adsorption and photocatalytic degradation of gas-phase UDMH under simulated sunlight by AgBr/TiO2/rGA
Ruomeng, Hou,Ying, Jia,Xiaomeng, Lv,Yuanzheng, Huang,Keke, Shen
, p. 12583 - 12594 (2021/04/14)
The degradation of UDMH has long been a concern for its harmful effects on humans and the environment. The current research on gas-phase UDMH treatment is limited and mainly focuses on ultraviolet light and high temperature environments, however the highly toxic substance NDMA is easily produced. In order to investigate the possibility of UDMH degradation in sunlight, AgBr/TiO2/rGA composites were prepared with the addition of different amounts of silver bromide. The highest UDMH conversion of AgBr/TiO2/rGA in humid air is 51%, much higher than the control group value of 24%, which can be ascribed to the synergy of adsorption and photocatalysis. The graphene and silver in AgBr/TiO2/rGA not only enhance the adsorption of light and UDMH, but also inhibit charge recombination and enhance electron-hole separation. More importantly, the temperature of the AgBr/TiO2/rGA composite was raised by the photothermal effect of graphene with promoted UDMH degradation efficiency. Furthermore, it is noted that NDMA was not detected in the optimal conditions.
MODELISATION GENERALE DES PROCESSUS REACTIONNELS INTERVENANT AU COURS DE LA SYNTHESE DE LA DIMETHYLHYDRAZINE ASYMETRIQUE PAR LE PROCEDE RASCHIG. QUANTIFICATION DES PRODUITS DE DEGRADATION (HYDRAZONE). I. FORMULATION DU MODELE. VALIDITE EN MILIEU DILUE. INTERPRETATION
Delalu, H.,Marchand, A.
, p. 2149 - 2162 (2007/10/02)
A kinetic model of Unsymetrical dimethylhydrazine (UDMH) formation by Raschig process has been established.Its application range runs from pH = 8 to 14.64 (4 mol.l-1 NaOH).The synthesis is controlled by the acid-base dissociation equilibria : (NH2Cl NHCl- + H+; (CH3)2NH2(+) (CH3)2NH + H+; (CH3)2NHNH2+ (CH3)2NNH2 + H+) and by the following elementary reactions : -Dimethylhydrazine elaboration molecular (NH2Cl / (CH3)2NH) and ionic (NHCl- / (CH3)2NH) processes -Dimethylchloramine formation from NH2Cl and (CH3)2NH2+ -UDMH catalytic oxidation by NH2Cl and dimethyldiazene (CH3)2N+=N- intermediate formation -Diazene decomposition to yield formaldehyde dimethylhydrazone (FDMH) -Degradation of (CH3)2N+=N- by NH2Cl -Alkaline hydrolysis of chloramine.The synthesis can be expressed by a differential system of which the integration allows to foresee the evolution of mixtures in terms of concentration, pH and temperature.In particular, it allows a numeric evaluation of FDMH, troublesome by-product of the UDMH manufacture.Significant examples selected in different pH ranges and concentration have permitted to test the coherence between experimental and calculated curves.