Poly-NIMMO

Poly(NIMMO) and PGN Prepolymers , in Proc. International Symposium on Energetic Materials Technology, 1995, 61-67, American Defence Preparedness Association, Arlington, VA. 

Composite propellants consist of an oxidizer (AP/AN/ADN), a metallic fuel such as Al, Mg etc and a binder, usually a polymer which also serves as a fuel. Vacuum stability tests (VSTs) suggest that composite propellants are intrinsically more stable than SB, DB and propellants. However, use of more exotic ingredients such as oxidizers (ADN and hydrazinium nitroformate, HNF), binders [poly([NiMMO)] and poly([GlyN)] are likely to introduce severe compatibility-related problems [30, 31]. Some recent research in this direction indicates that stability of such propellants is largely determined by the chemical and mechanical properties of propellants. However, early evidence of deterioration generally comes from a change in their mechanical properties rather than from chemical investigations [32]. 

There are a number of inert binders such as polyester, epoxy, polysulfide, polyurethane which have been reported as binders for composite propellants and plastic bonded explosives (PBXs). At present, hydroxy-terminated polybutadiene (HTPB) is regarded as the state-of-the-art workhorse binder for such applications. However, the recent trend is to use energetic binders such as poly [3,3-bis(azidomethyl oxetane)] [poly(BAMO)], poly (3-azidomethyl-3-methyl oxetane) [poly(AMMO)], PNP, GAP diol and triol, nitrated HTPB(NHTPB), poly(NiMMO), poly(GlyN) and nitrated cyclodextrin polymers poly(CDN) for PBXs and composite propellants in order to get better performance. 

The chemistry and properties together with applications of other energetic binders such as GAP, NHTPB, poly (NiMMO), poly (GlyN) and poly (CDN) will be described in Chapter 4 on propellants because of their extensive use in that segment of explosive industry. 

A1 20%, wax 10% and NTO 40%). This ammunition is designated as one-star MURAT IM with VOD [218] = 6880ms1. Also, CPX-413 [based on poly(NiMMO)/ HMX/NTO/K-10 Plasticizer) matches the performance of Composition while passing the UN Series-7 tests ranking it as an EIDS [219]. Presently, this formulation is not optimal but should prove a suitable candidate for further research. 

Structure (4.19) Poly(3-nitratomethyl-3-methyloxetane) [Poly(NiMMO)]... 

Poly(NiMMO) has been used in a variety of applications, not solely in explosives but also in gun and rocket propellants [128]. British scientists have done extensive research on synthesis, characterization and application of poly(NiMMO) as a binder for gun and rocket propellants. A team led by Leach examined a range of composite LOVA propellants based on poly(NiMMO) in combination with various fillers and plasticizers. At the end of their investigation, they concluded that it is possible to formulate propellants with an impetus of up to 1300J g-1 which still show a low response to shaped charge... 

To summarize, the cost of production of NHTPB is lower than that of poly(NiMMO) or Poly(GlyN). However, NHTPB s performance is poor in comparison to them. On the basis of trials conducted so far, it seems likely that poly(GlyN) will prove to be a world leader in the field of energetic polymers. A summary of the properties of energetic binders for use with both explosives and propellants is given in Table 4.6a,b. 

Current methodologies for the manufacture of energetic materials such as NHTPB, Poly(NiMMO) and Poly(GlyN) etc. use environmentally undesirable solvents such as dichloromethane. However, the adoption of the Montreal Protocol by most of the countries has limited the use of these halogenated hydrocarbons. To address current and futuristic legislations, DERA Scientists have developed various strategies to enable the manufacture of energetic materials in an environmentally friendly manner. Such an approach is to use Uquid or supercritical carbon dioxide as a solvent Carbon dioxide exhibits supercritical fluid behavior at a temperature >31.1 °C and a pressure >73.8 bar. 

End-modified, H2S04 hydrolyzed and K2C03 treated material meets the requirements. Similar to GAP and poly(NiMMO) acts as a binder and plasticizer depending on molecular weight. 

Imparts similar plashdzing effect on poly(NiMMO) as butyl NENA. However, its thermal stability is poor [168]. 

Marshall, E.J., Campbell, D., Cumming, A.S., Development of insensitive rocket propellants based on AN and poly(NiMMO). Proc. Insensitive... 

Leach, C.J., Debenham, D.F., Kelly, J., and Wilson, A. (1997) Advances in poly(NiMMO) composite gun propellants. Proc. 28th Inti Ann. Conf. ICT, Karlsruhe, Germany, June 24-27, 1997, Paper 2. 

Flynn, S., Fossey, D.R., Catton, D.G., and Wagstaff, D. (1998) Evaluation of poly(NiMMO) in reduced smoke propellants. Proc. 29th Inti Ann. Conf. ICT, Karlsruhe, Germany, June 30-July 03,1998, Paper 42. 

Cheun, Y.G., Cho, J.R., and Kim, J.S. (1995) An improved synthetic method of poly(NiMMO) and PGN prepolymers, in Proceedings of the International Symposium on Energetic Materials Technology, American Defense Preparedness Association (ADPA), Arlington, VA, USA, pp. 61-67. 

As discussed under explosives and propellants, a number of energetic binders GAP, NHTPB, poly(NiMMO), poly(GlyN), poly(BAMO), poly(AMMO) and BAMO-AMMO copolymers etc. have been reported in the recent past and are at various stages of development and introduction for bulk production of explosives and propellants for various applications. These polymeric binders are reasonably stable and are of established compatibility with a wide range of ingredients used for explosive and propellant formulations. The data on their explosive properties impact, friction and electric spark sensitivities, indicate that it is safe to handle these materials. However, there appears to be no report in the open literature on... 

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