Insensitive munition

The term insensitive munition (IM) is used to describe munition which is particularly safe to handle and which is difficult to initiate accidentally, but at the same 

Six tests are performed on each substance in order to classify them into one of these categories. The results of these tests can range from no reaction to complete detonation . Those tests are briefly summarized in Table 6.5. 

Since this area is so important, NATO has founded a Munitions Safety Information Analysis Center (MSIAC). 

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C. H. Detding and co-workers. Insensitive Munitions Characteristics ofAirEaunched In-Service Weapons Summay Keport of Fast Cook-offTimes, Reactions and Ha iards of Bombs, Pockets, Aircraft Guns, Air EaunchedMissiles, Mines and Torpedoes, Naval Weapons Center, China Lake, Calif., Sept. 1989. 

The polymers 1, 3 and 4 were 0-nitrated with nitric acid to give products containing nitrogen contents of 11.6 %, 19.9 % and 9.55 % respectively. Polymer 2, on the other hand, was nitrated with dinitrogen pentoxide in liquid carbon dioxide. Evaluations of these energetic polymers indicate that polymer 1 is a possible candidate for use in insensitive munitions. 

The explosives used for military purposes are different from those used in industry. Not only thermo mechanical power for destruction, but also various other characteristics are required. Experimental tests, such as slow cook-off fast cook-off, bullet impact, and sympathetic explosion tests, must be passed to meet the requirements for insensitive munitions (IM). The aerodynamic heating of warheads on flight projectiles is also an important factor in designing warheads. 

NTO or NTO/RDX or HMX have been reported as fillings to get insensitive munitions (IM) [155]. A comparison of PBXs based on TATB and NTO further confirms the same sensitivity levels while VOD of the NTO-based PBX is slightly higher. 

Insensitive Munitions and Some New Insensitive Explosives/Formulations... 

The safety of munitions received increased attention after the adoption of Insensitive Munition Policy by the US military. The IM Policy stipulated that all in-service... 

A formal international requirement for insensitivity was raised as far back as 1984 by NATO s Conference of National Armament Directors (CNAD) AC/310 Partnership Group on Safety and Suitability for Service Munitions and Explosives . As a result, a pilot NATO Insensitive Munitions Information Center (NIMIC) was set-up in the USA in 1988. Subsequently, after a couple of years when technologies for production of most ammunition of insensitive types were available and implementation and fielding was more important, the name NIMIC was changed to NATO s Munitions Safety Information Analysis Center (MSIAC) in December 2004. The advantages derived as a result of implementation of IM Policy are briefly described in Chapter 6 (Section 6.8). 

A new insensitive, cast-cured PBX called -135, has been developed in order to meet the requirements of US Navy s Insensitive Munitions Advanced Development Programfor High Explosives (IMAD/HE). PBXIH-135 has enhanced internal blast performance, improved non-vulnerability and penetration survivability characteristics compared with PBXN-109. Thermobaric explosives are required to defeat hard and deeply buried structures. PBXIH-135 thermobaric explosive which not only offers effective blast and thermal effects, but is also extremely insensitive to factors responsible for accidental detonation during transit or storage, may also be used for this purpose. 

Sjoberg, P. (1992) Low vulnerability characteristics and processing of cast-cured PBXs for insensitive munitions. Proc. Am. Def. Preparedness Association s Joint International Symp. on Energetic Materials Technology, New Orleans, Lousiana, USA, Oct. 5-7, p. 166. 

N-guanylurea dinitramide (commonly known as FOX-12) has low sensitivity and is an excellent candidate for insensitive munitions [72]. It is neither hygroscopic nor soluble in water. Its thermal stability is comparable to RDX and superior to that of ADN. The substitution of ammonium in dinitramide by an organic cation results in the change of combustion temperature and reactivity of the fuel. 

Leach, C.J., Debenham, D.F., Kelly,)., and Gillespie, K. (1999) Proc. NDIA Insensitive Munitions and Energetic Materials Technology Symposium, Tampa, El, USA, 1999. 

Damavarapu, R Mezger, M., Baum, K., and Lovatob, J.M. (1994) New approach to BDNPA/F. Insensitive Munitions Technology Symposium, American Defense Preparedness Association, VA, June 06-09, 1994. 

The Chinese scientists [123] have reported the preparation of nanoscale RDX (-50 nm) and nanoscale HMX (=70 nm) by an impinging method [124]. Researchers from China have also reported preparation and characterization of n-NTO and their data indicate that it decomposes at a lower temperature and at the same time, it is less sensitive to impact compared with m-NTO. This property of n-NTO is likely to be of tremendous significance for insensitive munitions [125]. The preparation of n-RDX particles with a mean size (=110-120 rim) but narrow distribution has also been reported by a novel method known as rapid expansion of supercritical solution (RESS) [126]. 

IMADP Insensitive Munitions Advanced Development Programme... 

NIMIC NATO Insensitive Munitions Information Center, USA (now MSIAC)... 

Recent developments of novel explosive materials have concentrated on reducing the sensitivity of the explosive materials to accidental initiation by shock, impact and thermal effects. The explosive materials, which have this reduced sensitivity, are call Insensitive Munitions, (IM). Although these explosive materials are insensitive to accidental initiation they still perform very well when suitably initiated. Examples of some explosive molecules under development are presented in Table 1.5. A summary of the significant discoveries in the history of explosives throughout the world is presented in Table 1.6. 

Solid propellant compositions which have been previously discussed all sulfer from the possibility of accidental initiation from fire, impact, electric spark, etc. Therefore, attention has turned to the development of insensitive munitions with particular emphasis on low vulnerability ammunition (LOVA). LOVA propellants contain RDX or HMX, an inert polymeric binder and a plasticizer. These composite propellants are less vulnerable to initiation than nitrocellulose-based propellants. 

This book outlines the basic principles needed to understand the mechanism of explosions by chemical explosives. The history, theory and chemical types of explosives are introduced, providing the reader with information on the physical parameters of primary and secondary explosives. Thermodynamics, enthalpy, free energy and gas equations are covered together with examples of calculations, leading to the power and temperature of explosions. A very brief introduction to propellants and pyrotechnics is given, more information on these types of explosives should be found from other sources. This second edition introduces the subject of Insensitive Munitions (IM) and the concept of explosive waste recovery. Developments in explosive crystals and formulations have also been updated. This book is aimed primarily at A level students and new graduates who have not previously studied explosive materials, but it should prove useful to others as well. I hope that the more experienced chemist in the explosives industry looking for concise information on the subject will also find this book useful. 

Thus Swedish scientists (at FOI) have very quickly synthesized, and established by their laboratory studies the favorable physical and chemical properties of DADNE, including its high performance and low sensitivity, resulting in a widely recognized useful new insensitive munition. Indeed, DADNE is now manufactured in quantity at NEXPLO-Bofors AB in Karlskoga. 

The extremely insensitive GUDN could be of particular interest for insensitive munitions. The theoretically-calculated detonation pressure of GUDN places it between TNT and RDX (25.7 GPa) [23]. The low sensitivity combined with performance is unique and unmatched in the literature. 

It is interesting that FOX-7 has the same C/H/N/O ratio as RDX or HMX. Although neither FOX-7 nor (and in particular not) FOX-12 meet RDX in terms of performance (detonation velocity and detonation pressure). Both compounds are much less sensitive than RDX and might be of interest due to their insensitive munition (IM) properties. Table 1.3 shows the most characteristic performance and sensitivity data of FOX-7 and FOX-12 in comparison with RDX. 

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