Gun propellants composition

Nitrocellulose can be quite hazardous if left to dry out completely therefore, it is usually stored and transported in 30% water or ethanol. Nitrocellulose is often dissolved in solvents to form a gel. For example, commercial explosives used for blasting purposes contain nitrocellulose dissolved in nitroglycerine, and some gun propellant compositions contain nitrocellulose dissolved in a mixture of acetone and water. 

Zentner, B. A., Reed, R., Calculated Performance of Gun Propellant Compositions Containing High Nitrogen Ingredients, 5th Inti. Gun Propellant Symp., Picatinny Arsenal, NJ, November 19-21, 1991, IV-278. 

All five processes requite plasticization of the nitrocellulose to eliminate its fibrous stmcture and cause it to bum predictably in parallel layers. Mechanical working of the ingredients contributes to plasticization and uniformity of composition. The compositions of representative nitroceUulose-based gun propellants are shown in Table 7. 

Polyhedral Boron Hydrides. These are used in neutron capture therapy of cancers (254), and as bum rate modifiers (accelerants) in gun and rocket propellant compositions. 

The data reported in the literature suggests that the replacement of DEP by Bu-NENA in the Dense NC/NG+ DEP/AP/AI/RDX-based composite modified double-base (CMDB) propellants results in increase in the burn rate by 18-20% at 70 kg cm pressure. The calorimetric value and percentage elongation also increase significantly. Further, thermal stability and sensitivity of such propellants are comparable with DEP-based CMDB propellants [184]. Bu-NENA is also a component of low vulnerability ammunition (LOVA) propellants [185, 186]. The introduction of butyl-NENA into SB, DB and gun propellants results in improvement of their mechanical properties and energetics and reduction in their sensitivity [187]. 

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. 

Considerable research and development has been undertaken in this area and it is estimated that a liquid gun propellant will probably come into service in the 21st century. Liquid gun propellants that are undergoing development are compositions which contain an aqueous ( 63%) solution of the crystalline salt hydroxylammonium nitrate (HAN) and a 50 50 mixture of nitromethane and isopropyl nitrate. 

Pyrotechnic primer compositions are often used to ignite gun propellants. The primer emits a burst of flame when it is struck by a metal firing pin, igniting the gun propellant. These primer compositions are therefore very sensitive to initiation and are capable of generating heat and shock. In order to reduce the sensitivity during the manufacturing process, the composition is used in the paste form. Examples of pyrotechnic compositions used in primers are presented in Table 8.5. 

US Gun ond Howitzer Propellants Composition (Including Residual Volatiles) and Some Characteristics... 

Interior Ballistic and Combustion Problems Associated with Advanced Composite Gun Propellants , Inst Chem Treib Explosivst, 269—84... 

F.H. Bell, Wafer Gun Propellant , USNatnl-Techlnform Rept, Thiokol Chem Corp, Brigham City (1973) (AD 771651/76GA) USGovtRep-Announce 74 (5), 159 (1974) CA 81, 5170 (1974) [The author reports on a plastic composite solid proplnt contg HMX. The proplnt is... 

Inatome, The Relationship Between Chemical Composition and Wear-Reducing Effectiveness of Some Laminar Additives for Gun Propellants Folyvinyltetrazole , BRL-MR-2512 (1975)... 

Propellants include both rocket and gun propellants. Most rocket propellants are either Hazard Class 1.3 composites, which are based on a rubber binder, and ammonium perchlorate (AP) oxidizer, and a powdered aluminum (Al) fuel or Hazard Class 1.1 composites, which are based on a nitrate ester, usually nitroglycerine (NG), nitrocellulose (NC), HMX, AP, or polymer-bound NC. If a binder is used, it usually is an isocyanate-cured polyester or polyether. Some propellants contain combustion modifiers, such as lead oxide. 

Glycidyl azide polymer was originally developed in the USA as an -> Active Binder tor - Composite Propellants. Because this gas-producing component has been shown to have a low explosion temperature, it has been used in recent years as an active binder compound in -> LOVA gun propellant. 

Nitroguanidine (NQ) was first prepared by Jousselin in 1887 (Fig. 1.3). However, during WWI and WWII it only found limited use, for example in formulations with AN in grenades for mortars. In more recent days NQ has been used as a component in triple-base propellants together with NC and NG. One advantage of the triple-base propellants is that unlike double-base propellants the muzzle flash is reduced. The introduction of about 50 % of NQ to a propellant composition also results in a reduction of the combustion temperature and consequently reduced erosion and increased lifetime of the gun. NQ can be prepared from dicyandiamide and ammonium nitrate via guanidinium nitrate which is dehydrated with sulfuric acid under the formation of NQ ... 

DANP is a colorless, or yellow, oily liquid. It can be distilled under reduced pressure (vacuum distillation). It is an excellent high-energy plasticizer for use in making flexible sheet explosives when mixed with RDX, TNT, or HMX. It can also be used in place of nitroglycerine for dynamites, rocket propellants, gun propellants, and explosive compositions. ... 

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