Nitrate ester groups

Displacements with azido anion are tolerant of many pre-existing explosophoric groups but the nitrate ester group readily undergoes displacement as seen for the synthesis of bis(2-azidoethyl)nitramine (13) from Ai-nitrodiethanolamine dinitrate (12) (DINA). " ... 

NHTPB [Structure (4.18)] is a liquid polymer, whose viscosity can be varied by changing the percentage conversion of double-bonds to dinitrate ester groups. It is made by conversion of a percentage of the double bonds in HTPB to epoxide groups and then to nitrate-ester groups by the reaction with... 

Mixed pentaerythritol esters have also been described [50] that contain in their molecule hydroxyl groups substituted by organic acids, which possess nitro groups either in ester form or as C-nitro compounds joined with the acid, alongside simple nitrate ester groups. 

A benzylic fluorine atom that is also activated by an adjacent nitrate ester group is easily replaced with hydrogen in catalytic hydrogenation under mild conditions (Table 4).65... 

In an investigation at laboratories of ICI the surface of treated film was scraped mechanically and the scrapings were analysed by infra-red and other spectroscopic techniques this indicated that nitro groups, nitrate ester groups, and carbonyls were formed in the surface layer. 

The propellants derived from nitrate ester-based binders possessed the undesirable characteristics associated with nitrate ester groups such as thermal instability, hydrolytic instability, and impact instability (especially for highly nitrated compositions). For this reason a study was undertaken to prepare polymeric binders in which oxygen is carried in the form of the more thermally and hydrolytically stable nitro group. Aerojet General Corp., working with both the Purdue and the Ohio Research Foundations, carried out the bulk of these studies. The following are typical of the condensation monomers synthesized by Aerojet ... 

As you now know, aliphatic organic compounds belong to the alkane, alkene, and alkyne classes of compounds. Aliphatic explosives fall into both the open-chain and cycloaliphatic groups. The major sources of oxidizer in most aliphatic explosives are from the nitrate ester group (—ONO2) and the nitramine group (—NH—NO2). The nitrate esters are usually made by direct nitration of an... 

When a compound containing a nitrate ester group is stirred with cold concentrated sulfuric acid, nitric acid is liberated. This is detectable with diphenylamine or A,V -diphenylbenzidine, each of which gives an intense blue color. 

The nitrate ester group is irreversibly reduced in water/alcohol solutions in the potential range —0.2 V to —1.3 V at a dropping mercury electrode, via a two electron reaction ... 

When the concentration of alcohol is increased, the reduction is displaced towards more negative potentials. The reduction of polynitrate esters will occur at more positive potentials when the number of nitrate ester groups in the molecule is increased. The change will be approximately 0.1 V per each new nitrate ester group. Under certain conditions (water/methanol solutions), the reduction of the separate nitrate ester groups can be detected. 

A comparison between the polarograms in Fig.3 and 4 shows that the reduction of a nitro group also will produce a peak considerably narrower and more well-defined than the reduction of a nitrate ester group will do. This is caused partially by the fact that the nitro... 

Nitrotoluenes and nitrate esters are reduced in the same potential range. By carefully selecting the methanol concentration of the solution, a mixture of two nitrotoluenes and one nitrate ester can be determined. The polarograms are influenced by the methanol content of the solution, and also by the fact that the nitrate ester group is reduced by 2 electrons and the nitro group by 6 electrons, and that the nitrate ester group reduction is strongly irreversible. 

In order to prevent those reactions, stabilizers are added to the propellant. The function of the stabilizer is to react sufficiently fast with the nitrogen dioxide formed, thereby preventing the gas formed to take part in the catalytic decomposing reaction with more nitrate ester groups. 

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