One-step green method to prepare progressive burning gun propellant through gradient denitration strategy

Ding

et al. 2023

Self Cite

Improving the progressive burning performance of gun propellant is an effective approach to increase the muzzle velocity of bullet. The seven-hole gun propellant characterized by a perforated structure with progressive burning performance has a broad application in the field of medium and small caliber weapons. Therefore, researches aiming to improve its burning performance are indispensable. In this paper, a seven-hole gun propellant with the gradiently-denitrated layer structure (GDLS) that the energetic functional groups increased gradually from the surface to the inside was designed and fabricated. Theoretical calculation indicated that the nitrogen content of nitrocellulose in seven-hole gun propellant has a positive relationship with the burning rate coefficient and impetus. The results of burning calculation showed that the progressive burning performance of seven-hole gun propellant were improved with the thickness of GDLS increases or the burning rate coefficient of the surface decreases. Moreover, the seven-hole gun propellant with GDLS was successfully prepared, named gradiently denitrated sevenhole gun propellant (GDSGP), which was proved by the results of FT-IR, Raman and SEM. The different denitration conditions enabled the GDSGP with a good progressive burning performance, as confirmed by closed bomb test. Furthermore, the progressive burning performance of GDSGP increased first and then decreased with extending the denitration time. On the basis of design and study of GDSGP, the control and optimization of the burning performance of GDSGP will be more accurate in practical applications.

Section: Structural Characterization Of Gdsgpsupporting

confidence: 85%

Design and fabrication of gradiently‐denitrated layer structure of seven‐hole gun propellant and its burning performance

Ding

et al. 2023

Self Cite

“…The combustion performance of the raw gun propellant and the gradiently denitrated gun propellant under different conditions was investigated using the closed bomb vessel test. Figure 4 number of À ONO 2 groups on the gun propellant surface layer and a lower energy density, leading to a reduction in gas generation and an increase in combustion time [11,19,20]. Generally speaking, the greater the B m and ΔL values, the better the combustion progressivity of the gun propellant.…”

Section: Combustion and Interior Ballistic Performancementioning

confidence: 99%

“…The methyl violet paper did not change color until the heating time exceeded 70 min and the sample detonated only after continuous heating for more than 5 h, which indicated a good stability of the gradiently denitrated NC/NG/TEGDN based gun propellant. Nitrogen oxides (NO x ) is known to accelerate the decomposition and destabilization of gun propellant [11,34]. Part of the NO x gas without being absorbed by the stabilizer will react with other decomposition products [35].…”

Section: Physical and Chemical Propertiesmentioning

confidence: 99%

“…Nevertheless, the introduction of deterring agents, such as dibutyl phthalate (DBP) [5,6], dioctyl phthalate (DOP) [7], camphor [8], dinitrotoluene (DNT) [9,10] and so on, causes a low oxygen balance of the gun propellant, thereby generating more combustible gases such as carbon monoxide and hydrogen because of the incompletely oxidized for the carbon and hydrogen elements during the combustion process. These hightemperature combustible gases are mixed with the muzzle air, leading to a series of chain reactions and generating the flame [11,12]. In addition, deterring agent is a non-energetic substance.…”

Section: Introductionmentioning

confidence: 99%

“…Liang et al [3] proposed an energetic composite deterring strategy using a high-oxygen balance, easily decomposed energetic composite deterring agent poly neopentyl glycol adipate (PNA), combined with triethylene glycol dinitrate (TEGDN) to treat the gun propellant, which reduced the intensity of the firing smoke and flame substantially compared to DBP deterred gun propellant. Different from the deterring strategy, a chemical denitration strategy was proposed by Li et al In detail, a single-based gun propellant (energy component is only nitrocellulose (NC)) was investigated to achieve combustion progressivity by removing part of the surface nitrate group of the gun propellant through denitration agent [11,19]. It was tentatively confirmed from theoretical calculations and ballistic tests that the gradiently denitrated gun propellant had the advantages of high oxygen balance, low combustion smoke concentration and small flame area [20].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Surface denitration structure on dynamic combustion performance and muzzle flame of mixed nitrate gun propellant

Chen

et al. 2023

Self Cite

The gun propellant is an inaccessible energy and fuel for projectile to achieve destructive capability in a weapon system. Nitrocellulose/nitroglycerine/triethylene glycol dinitrate(NC/NG/TEGDN) based gun propellant with higher energy level than single‐based gun propellant can meet the demands of modern warfare. Currently, deterring strategy is commonly used to improve the combustion progressivity of NC/NG/TEGDN based gun propellant, together with aggravating the harmful emission phenomena such as muzzle smoke and flame. Therefore, it is essential to design and fabricate NC/NG/TEGDN based gun propellant with both good combustion progressivity and low characteristic signal. In this work, a gradiently denitrated NC/NG/TEGDN based gun propellant was successfully prepared by denitration strategy, whose structure was confirmed by FT‐IR, Raman and SEM. Here, closed bomb vessel test and interior ballistic test were conducted. The results showed that the gradiently denitrated NC/NG/TEGDN based gun propellant exhibited better combustion progressivity and interior ballistic performance than raw gun propellant, and these properties can be controlled by modulating the degree of denitration. Meanwhile, the change laws of the muzzle smoke and flame of the gradiently denitrated NC/NG/TEGDN based gun propellant were investigated by the smoke box method and high‐speed photography. Furthermore, a lower characteristic signal for the gradiently denitrated NC/NG/TEGDN based gun propellant was found compared to the deterred gun propellant by theoretical calculations. This work provides a new idea for preparing and applying a gun propellant with excellent comprehensive performance, including high energy, good combustion progressivity and low characteristic signal.

Reaction Kinetics Model of Surface‐Denitrated Spherical Gun Propellant

Ding

et al. 2022

Self Cite

Gun propellant with progressive burning performance plays an important role in improving the comprehensive performance of barrel weapon. At present, surfacedenitrated gun propellant prepared by removing energetic functional groups (À ONO 2 ) directionally in the surface layer of gun propellant, is an original progressive burning gun propellant. In this study, the reaction kinetics of denitration process of spherical gun propellant was established by a simple weighing method based on the shrinking unreacted core kinetic model (SUCK model) of solid-liquid reaction. The SEM was used to obtain the change of the cross-sectional microstructure of spherical gun propellant before and after the denitration reaction, confirming the core-shell structure of surface-denitrated spherical gun propellant.Then, the denitration reaction rate of spherical gun propellant was studied under different denitration reaction temperatures and reaction times. Meanwhile, the Arrhenius formula was used to calculate the activation energy of the denitration reaction. The results showed that the denitration reaction of spherical gun propellant was controlled by the diffusion of denitration solution in the solid product layer and the value of the apparent activation energy (E a ) is 105.7 kJ • mol À 1 . This work not only establishes the kinetic model of surface-denitrated spherical gun propellant but also provides a theoretical and practical basis for the controllable and efficient preparation of surface-denitrated gun propellant.