Modified double-base propellants

M.C, Philpot, Gas Chromatographic Determination of Plasticizers and Stabilizers in Composite Modified Double-Base Propellants , AnalChem 41 (1), 166-8 (1969) CA 70, 49143 (1969) 49) J. Trauchant, Chromato-... 

A third type of propellant, the composite modified-double-base propellant, represents a combination of the other two types. These propellants are made from mixtures of nitroglycerine and nitrocellulose or similar materials, but with crystalline oxidizers such as ammonium perchlorate also included in the matrix. 

One extremely important point to realize is that different propellant types may have different rate-controlling processes. For example, the true double-base propellants are mixed on a molecular scale, since both fuel and oxidizing species occur on the same molecule. The mixing of ingredients and their decomposition products has already occurred and can therefore be neglected in any analysis. On the other hand, composite and composite modified-double-base propellants are not mixed to this degree, and hence mixing processes may be important in the analysis of their combustion behavior. 

CMDB Composite modified double-base (propellant)... 

When nitramine particles such as HMX or RDX particles are mixed with a doublebase propellant, nitramine composite-modified double-base propellants are formulated. Since HMX and RDX are stoichiometrically balanced materials, the use of these nitramine particles leads to a somewhat different mode of combustion as compared to AP-CMDB propellants. Since each nitramine particle can burn independently of the base matrix at the burning surface, a monopropellant flamelet is formed in the gas phase from each particle. The monopropellant flamelet diffuses into the reactive gas of the base matrix above the burning surface and a homogeneously mixed gas is formed. 

Kubota, N Energetics of HMX-Based Composite-Modified Double-Base Propellant Combustion, J. of Propulsion and Power, Vol. 15, No. 6,1999, pp. 759-752. 

Singh, H., Advances in Composite-Modified Double-Base Propellants (Eds. Varma, M., and Chatterjee, A. K.),... 

BSQ. A modified double-base propellant developed at ABL. Its compn props are given in conf "Propellant Manual", SPIA/M2(1959), Unit No 519... 

Pentaerythritol trinitrate is used in explosives and propellants, partly or wholly replacing nitroglycerine. Americans believe that there is 2.0 % pentaeiythritol trinitrate in modified double-base propellants with cellulose nitrate and an adhesive... 

Double-base propellants may be formulated to include fuels such as aluminum metal, oxidizers such as ammonium perchlorate (AP), or energetic materials such as the nitramines RDX or HMX. The resulting compositions are termed composite-modified double-base propellants. A further modification, the addition of a polymer that is curable with a low molecular weight curing agent, allows formulation of propellants with much improved mechanical properties over the temperature range of usage. Such propellants are termed elastomer-modified composite double-base (EMCDB) propellants. 

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