Mechanism of thermal decomposition of double base propellants

Abstract

Thermogravimetric studies were carried out with double base propellants to find out the rate‐determining stage and to understand the mechanism. The decomposition process can be divided into 3 stages as follows: Diffusion of nitroglycerin takes place in the temperature range 120°C–160°C. Two processes occur in the temperature range 170°C–205°C, namely the dissociation of nitroglycerin and the cleavage of the CO bond, the later being the rate‐determining step. The cleavage of the CO bond is followed by a considerable decomposition of nitrocellulose.

Fullerene Stabilizer 4,11,15,30-Tetraarylamino Fullerenoarylaziridine: Regioselective Synthesis, Crystallographic Characterization Derivatives, and Potential Application as Propellant Stabilizer

“…Double-base propellants contains many nitrate compounds, including nitrocellulose (NC) and nitroglycerin (NG), which decompose to generate nitroxide radicals during long-term storage. NC is a highly flammable polymer formed by nitrating cellulose via exposure to nitric acid or another powerful nitrating agent; it has usually been applied to various military and civilian applications − It is noteworthy that these nitroxide radicals accelerate the decomposition of nitrate compounds, thus deteriorating the propellant’s performance, burning, and even explosion. − The stabilizers are usually added to the propellants by absorbing the nitrogen oxides produced from nitrate compound decomposition to improve stability, thereby restraining further autocatalytic decomposition of the nitrate compounds. − The stabilizers commonly applied to double-base propellants are mainly aniline and urea derivatives, − such as diphenylamine (DPA), 2-nitrodiphenylamine (2-NDPA), N -methyl- p -nitroaniline (MNA), N , N’ -diethyl- N , N’ -diphenylurea (C1), N , N’ -dimethyl- N , N’ -diphenylurea (C2), 1,1-diphenylurea (AK-I), and 3-methyl-1,1-diphenylurea (AK-II). Among them, DPA, 2-NDPA, and MNA are basic and can rapidly combine with nitrogen oxides, inhibiting the autocatalytic decomposition of nitrate compounds and stabilizing the propellants.…”

Microcellular Oblate Propellant with Skin-core Structure Deterred by Poly(neopentanediol adipate)

“…In order to meet the requisite high muzzle velocity and low chamber pressure in the firing process, deterring and coating technology are the common and effective methods to realize the progressive combustion performance of oblate propellants [1]. Dibutyl phthalate (DBP) is used as the traditional deterrent for double-base oblate propellants, and oblate propellants deterred by DBP exhibit high loading densities and progressive combustion performance [2]. However, DBP desensitized double-base oblate propellants produce a lot of muzzle flash and smoke in the firing process, which goes against the shooting for soldiers.…”