Suitability of nitrogen rich compounds for gun propellant formulations

The influence of two selected bistetrazoles, 5,5′‐bis(1H‐tetrazolyl)‐amine (BTA) and 5,5′‐hydrazinebistetrazole (HBT), on the combustion behavior of a typical triple‐base propellant was investigated. Seven propellant formulations, one reference and six others incorporating 5 %, 15 %, and 25 % of either HBT or BTA compounds, respectively, were mixed and extruded into a cylindrical, no perforations, geometry. The resulting propellants showed high burning rates, up to 93 % higher than the reference formulation at 100 MPa. However, the increase in burning rates came at the cost of higher burning rate dependency on pressure, with a pressure exponent as high as 1.4 for certain formulations. HBT‐containing propellants showed notably lower flame temperature when compared to the reference formulation, with a flame temperature reduction of up to 461 K for the propellant containing 25 % HBT. The thermal behavior of the propellants was also investigated through DSC experiments. The addition of bistetrazoles provided lower decomposition temperatures than the pure nitrogen‐rich materials, indicating that the two compounds probably react readily with the −ONO2 groups present in the nitrocellulose and the plasticizers used in the formulation. The onset temperature of all propellants remained within acceptable ranges despite the observed decrease caused by the addition of the bistetrazole compounds.

Section: Burning Ratessupporting

confidence: 55%

Burning Rates and Thermal Behavior of Bistetrazole Containing Gun Propellants

Lavoie

Petre

Paradis

et al. 2016

“…More powerful propellants with balanced-stoichiometric amounts of oxidants and fuel are demand in the military throughout the world. However, although balanced and more powerful propellants lead to the increase of muzzle velocity, chamber pressure and rate of fire, the erosion of gun barrel due to high temperature burning gas of propellants become increasingly serious and markedly shortened the useful of barrel life [1][2].…”

Section: Introductionmentioning

confidence: 99%

Robust Microencapsulated Silicone Oil with a Hybrid Shell for Reducing Propellant Erosion

Sun

Xiao

2017

A morphologically stable silicon oil microcapsule base polystyrene as shell modified with TiO2 and Si3N4 nanoparticles was synthesized, characterized and applied as an inhibitor for high energy propellant to reduce erosion of gun barrel. The composite microcapsules were obtained by an eco‐friendly method. Embedding heat‐resistant TiO2 and Si3N4 nanoparticles in polystyrene shell enhances the reliability of polymeric shell. The anti‐erosion effect of composite microcapsules for high energy propellant was investigated by using an erosion tester. Results showed that the erosion property of high energy propellant with composite microcapsule was significantly decreased when compared to control sample (without microcapsules). It showed a decrease of 20.6 % in erosion mass when 7 wt.% of composite microcapsules were added to the high energy propellant. Moreover, the anti‐erosion efficiency of composite additives exhibited an increasing trend with the increase of their contents. The pressure and time history confirmed that the composite microcapsules also have ability to adjust the combustion performance of high energy propellants. The developed silicon oil microcapsule shows a potential application for propellant erosion additive.

“…With the increase of requirements for contemporary artillery that fire farther, faster, and more accurately, various kinds of high energy propellants containing a certain amount of cyclotrimethylene trinitramine (RDX) have been widely used nowadays [1][2]. Many researches have proved that RDX as a high energetic explosive is highly thermally and chemically erosive to the gun barrel [3].…”

Section: Introductionmentioning

confidence: 99%

Effects of an Organic‐inorganic Nanocomposite Additive on the Combustion and Erosion Performance of High Energy Propellants Containing RDX

Sun

Xiao

2017

A nanocomposite microsphere consisting of solid paraffin, nano-TiO 2 , nano-BN, zeolitic imidazolate framework-67 particles and polymethyl methacrylate was prepared and applied as a functional additive for high energy propellants (with about 23 wt % RDX) to reduce the barrel erosion and improve its combustion performance as well. High energy propellants modified with the nanocomposite were manufactured by a solvent extrusion technique. According to the scanning electron microscope and differential scanning calorimetry results, there exists a good compatibility between the nanocomposite and propellant matrix. The energy and combustion performance as well as erosion of the modified propellants were studied by a closed bomb test and an erosion tube device, respectively.Results showed that compared with the unmodified propellant, both the erosion and energy performance of modified high energy propellant gradually decreased with the increase of nanocomposites contents. When the content of nanocomposites was 5.1 %, the erosion mass of the modified propellant reduced to 37.0 % while the propellant force only decreased 5.7 %, indicating that the nanocomposite has enormous ability to improve gun erosion resistance while barely affect energy performance of propellant. Furthermore, the closed bomb burning curves of the samples showed that addition of nanocomposites to propellant matrix could prolong the combustion time, efficiently inhibit the initial generation rate of combustion gas, and further achieve the progressive burning of the propellants.