Energetic nitrate esters

Some examples of nitrate ester incorporation into caged molecules have been reported 1,3,5,7-tetranitroxyadamantane (97) has been synthesized in three steps from 1,3,5,7-tetrabromoadamantane (96) and 1,4-dinitroxycubane (99) ° has been synthesized from the nitration of the corresponding diol (98). 

The Henry condensation of nitroform and terminal dinitromethyl compounds with formaldehyde and other aldehydes, followed by nitration of the resulting alcohol functionality, has been used to synthesize numerous explosives. The nitrate esters (104), (105), (106) and (107)155 ij yg ijggjj synthesized from the action of absolute nitric acid on the parent alcohols. In a similar manner, NMHP (109) is synthesized from the condensation of TNHP (108) with formaldehyde, followed by O-nitration with absolute nitric acid.  

A number of secondary high explosives containing both nitramine and nitrate ester functionality have been reported. Aliphatic examples include A-nitrodiethanolamine dinitrate (DINA) (110), prepared from the nitration of diethanolamine with nitric acid-acetic anhydride in the presence of zinc chloride,and A,A -dinitro-A,A -bis(2-hydroxyethyl)oxamide dinitrate (NENO) (111), prepared from the mixed acid nitration of A,lV -bis(2-hydroxyethyl) oxamide . 

A number of nitramine-nitrate explosives have been prepared by Millar and co-workers from the action of dinitrogen pentoxide on aziridines and azetidines (Section 5.8). Millar and co-workers used their aziridine ring-opening nitration methodology (Section 5.8.1) to synthesize the high performance melt-castable nitramine-nitrate explosive known as Tris-X 

Agrawal and co-workers prepared some energetic explosives containing nitrate ester, nitramine and aromatic C-nitro functionality within the same molecule and studied their thermal and explosive properties l-(2-nitroxyethylnitramino)-2,4,6-trinitrobenzene 

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Since NG is highly shock-sensitive, other types of nitrate esters can be used to formulate non-NG double-base propellants. DEGDN, TEGDN, and TMETN are typical examples of energetic nitrate esters that can be mixed with NC. These nitrate esters are less energetic than NG, and their sensitivities to friction and mechanical shock are accordingly lower than those of NG. Thus, the mass fraction of desensitizer used in propellant formulation can be lower than when NG is involved. The physicochemical properties of these nitrate esters are shown in Tabs. 2.3 and 2.5-2.7. 

This change in editorial leadership has resulted, perhaps inevitably, in a change in editorial policy which is reflected in the contents of Volume 8. There has been a marked de-emphasis on the inclusion of organic parent compounds followed by an exhaustive and voluminous cataloging of azide, azido, azo, diazido, diazonium, diazo, nitro, dinitro, polynitro, hitr amine, nitrate (esters and salts), dinitrate, poly nitrate, nitroso, polynitroso, chlorate, perchlorate, peroxide, picrate, etc, derivatives — regardless of whether any of these derivatives exhibit documented explosive or energetic properties. Only those materials having such properties have been included in this volume... 

A huge number of ester and carbonate derivatives of polynitroaliphatic alcohol have been synthesized driven by the search for new explosives and energetic plasticizers and oxidizers for propellant and explosive formulations. Most of these are derived from 2-fluoro-2,2-dinitroethanol and 2,2,2-trinitroethanol ° and have excellent oxygen balances. Some examples are illustrated above (168-174) but more comprehensive lists can be found in numerous reviews. " " Direct esterification of polynitroaliphatic alcohols with nitric acid, mixed acid, or acetic anhydride-nitric acid has been used as a route to mixed polynitroaliphatic-nitrate ester explosives. ... 

The energetic nature of the N-NO2 group means that At-nitro-based explosives are some of the most powerful explosives available and these have largely superseded aromatic C-nitro compounds for military applications. Many nitramines exhibit high brisance and high chemical stability in combination with a favourable low sensitivity to impact and friction compared to nitrate ester explosives of similar power. 

Drees and co-workers synthesized a number of energetic azido plasticizers whose structures are based on those of known nitrate ester plasticizers. EGBAA (3), DEGBAA (4), TMNTA (5) and PETKAA (6) are synthesized from the corresponding chloroacetate esters with sodium azide in DMSO. 

In contrast to other crystaUine nitrates, pentaerythrol tetranitrate (PETN C Hg(0N02)4) is a crystalline nitrate ester similar to NG and NC. Though PETN is one of the most powerful energetic materials used in explosives, no excess oxidizer fragments are formed when it decomposes. Thus, PETN is not used as an oxidizer of propellants. 

BAMO is also copolymerized with nitratomethyl methyl oxetane (NIMO) to formulate the energetic liquid polymer BAMO-NIMO. Since NIMO is a nitrate ester containing an -O-NO2 bond in its molecular structure, BAMO-NIMO copolymer is more energetic than BAMO-THF copolymer. The chemical structures of BAMO and NIMO are both based on the oxetane structure, and the structure of the BAMO-NIMO copolymer is shown in Fig. 4.10. 

The addition of crystalline oxidizers such as ammonium nitrate or potassium nitrate to nitrate esters or energetic polymers leads to the formation of composite ex-... 

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