PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2023
·Vol. 48
·期 5
·e202200253
·
IF 1.8
Ting You,An Chen,Yimei Liao,Qiang Tian,Xiaohui Duan
To shed light on the structure-property relationship of a methylnitroguanidine (MeNQ)-nitroguanidine (NQ) eutectic, its thermal behavior and microstructure were studied by various techniques. The eutectic composition of MeNQ-NQ with the lowest melting temperature ( T m ) of 149.9 °C was at the mole ratio of 7 : 3, as determined by temperature-composition ( T-X ) and melting enthalpy-composition ( H-X ) diagrams. The MeNQ-NQ eutectic exhibited a homogeneous network structure composed of the plate-shaped MeNQ and acicular NQ enriched phases that resulted in a uniform melting around the T m observed by in situ variable temperature optical microscopy. The X-ray diffraction from MeNQ-NQ eutectic showed peaks that were shifted to low scattering angle, an indication of the expansion of its crystal lattice and the formation of solid solutions. Small-angle X-ray scattering from the sample showed a rough interface between the MeNQ- and NQ-enriched phases. Infrared spectral data showed absorption peaks due to −NH 2 and −CH 3 groups that were red shifted relative to the raw materials, an indication of hydrogen bond interactions between MeNQ and NQ molecules.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 23
·13808-13816
·
IF 3.108
Cheng-Yang Cao,Song Lu,Dan Zhang,Lun-Lun Gong,He-Ping Zhang
The 5AT/Sr(NO3)2 mixture has recently attracted attention as a gas-generating agent for use in novel fire-suppression applications. However, it cannot provide the desired combustion behavior alone. Thus, nitroguanidine (NQ) was added as a fuel component to 5AT/Sr(NO3)2 in attempt to improve the mixture's combustion behavior. The effects of NQ on the thermal and burning characteristics of 5AT/Sr(NO3)2 were investigated. Thermogravimetry-differential scanning calorimetric (TG-DSC) analysis with four heating rates (5, 10, 15, 20 K min−1) under a nitrogen atmosphere was performed to determine the thermal characteristics and non-isothermal reaction kinetic parameters. The addition of NQ decreases the activation energy of the Stage II and III decomposition reaction, and accelerates the redox reaction and decomposition of Sr(NO3)2. Thermodynamic calculations and measurements of temperature profile and liner burning rates were performed to evaluate the combustion characteristics. Adding NQ decreased the adiabatic combustion temperature, outlet temperature, average flame height, flame oscillation frequency and pressure exponent of Vieille's equation, and increased the gas output and linear burning rate. Notably, mesa burning occurred when NQ was added, the mechanism of which is elaborated using a physical combustion model. The analysis deepens the understanding of when the gas-phase or condensed-phase reactions control the burning characteristics of the composite propellant.
研究领域:
材料科学
·
燃烧学
·
推进剂研究
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Ling Chen,Anning Sun,Jianwei Zhang,Derong Meng,Peichen Han,Feiyun Chen,Fengqiang Nan,Ping Du,Weidong He
High-energy propellant always encounters deficient mechanical properties and unstable combustion behavior under low temperature, leading to difficulties in subsequent use. Herein, the reinforcement filler carbon nanofibers (CNFs) were pioneered introduced into nitroguanidine propulsion, meanwhile, the molecular model and structure–function relationship of high-solid content propellant system was constructed. A sequence of characterizations manifested that CNFs were integrated well in propulsion system. The result of mechanical properties demonstrated that anti-impact strength increased with the increase content of CNFs in propellant, and a proper content range from 0.25 % to 1.0 % exerted better mechanical strength than that of high content under different temperature conditions. A “wire-tie” structure acting bridging effect that exhibit buffer exoenergic effect in terms of the enhancement mechanism was proposal as well, combing the theoretical calculated interaction of nitroguanidine (NQ) and nitrocellulose/nitroglycerin (NC/NG). Additionally, the analysis of thermal decomposition kinetic of propellant by conventional iso -conversional rate methods demonstrated that the addition of CNFs can could furtherly reduce the activation energy of NQ-GP, which is accord with the result of linear fitting methods. It also demonstrated that the thermal decomposition behavior of propellant was influenced by different high-pressure conditions and CNFs content, including T p and heat-release. Additionally, propellant integrated with CNFs burning steadily under different temperatures, and the burning rate coefficient and burning pressure exponent of propellant could be also flexible tuned with proper content of CNFs. Hence, the presented study highly broadens the application scope of reinforcement nanofiller, and will be potential of value to the community development in high-energy and high strength gun propulsion in aspect of combining experimental and theoretical calculation.
研究领域:
材料科学
·
推进剂工程
·
分子动力学
✓ 已验证
产品关联
DOI
高影响因子
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2021
·Vol. 46
·期 8
·1276-1285
·
IF 1.887
Jiachao Bai,Ergang Yao,Libai Xiao,Jie Zhou,Yinghui Ren,Fengqi Zhao,Wenzhong Shen
Six nitroguanidyl-functionalized nitrogen-rich compounds were synthesized and characterized by EA, FT-IR, and NMR. In addition, the crystal structures of ANPTz, CABNG, and FANG were further determined by X-ray single-crystal diffractometer. The thermal decomposition behaviours were studied by the DSC-TG-FTIR-MS coupling technique and the results showed that all the compounds had good thermal stability, among which ANPTz had the best thermal stability ( T d =211.03 °C). Also, HCN, CO 2 , H 2 O, and NO 2 were released during thermal decomposition process. The self-accelerating decomposition temperature ( T SADT ) and thermal explosion critical temperature ( T b ) were calculated to evaluate thermal safety, and the relative order was as follows: FANG ( T SADT =198.68 °C, T b =209.97 °C)> ANPTz ( T SADT =194.12 °C, T b =208.63 °C)> BANTz ( T SADT =182.52 °C, T b =207.54 °C)> AANG ( T SADT =180.04 °C, T b =188.35 °C)> CABNG ( T SADT =176.80 °C, T b =187.32 °C)> MABNG ( T SADT =173.61 °C, T b =184.29 °C). The results indicated that FANG had the acceptable sensitivity ( IS =7.84 J), good detonation performance ( D =8551 m⋅s −1 , P =32.33 GPa), and the significant catalytic effect (the decomposition temperature of RDX decreased by 8.31 °C).
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Ling Chen,Anning Sun,Derong Meng,Binbin Wang,Feiyun Chen,Fengqiang Nan,Ping Du,Weidong He
High energy, high strength, and stable combustion character are the basic requirements of a modern gun propellant (GP). Herein, graphene nanosheets (GNSs) are introduced into the nitroguanidine gun propellant (NQ-GP) as reinforcements to modify its comprehensive performance. A series of in-depth characterizations were conducted to characterize the structure and composition of the propellant, demonstrating that GNSs integrated well in the propellant system. The result of mechanical properties manifested that the anti-impact strength increased with the increase in the content of GNSs in the propellant, and GNSs with a low content of 0.5% in the GP exerted better mechanical strength than those with a high content under different temperature conditions; the brickwork bridging effect enhancement mechanism was proposed as well. Besides, the thermal decomposition character was investigated under different heating conditions like programmed and high pressure. It revealed that GNSs with a high content can produce a catalytic effect on the thermal decomposition process of the propellant like the heat release. Additionally, the analysis of the thermal decomposition kinetics of the propellant by the method of Friedman demonstrated that the addition of GNSs with a proper content could further enhance the activation energy of NQ-GP with thermal stability, which is opposite to the result of linear fitting methods of Kissinger and Ozawa. The results obtained by the different methods were likely to vary with the action mechanisms of the different systems or thermal decomposition stages. It also demonstrated that different high-pressure conditions and GNS contents can produce obvious influence on the thermal decomposition behavior of the propellant, such as Tp and heat release. Moreover, it was found that the introduction of GNSs would not influence the burning stability of the propellant and that the burning rate coefficient (a) and the burning pressure exponent (n) could also be modified with the proper content of GNSs. Hence, the work presented herein highly broadens the application scope of the reinforcement nanofiller and will be of potential value to the community development in high-energy and high-strength GPs.
研究领域:
材料科学
·
推进剂工程
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
Plasmonics
·
2016
·Vol. 11
·期 6
·1573-1578
·
IF 2.146
Zhang Xianhui,Zheng Lei,He Yi
We report a simple, facile, selective, and highly sensitive colorimetric sensor for nitroguanidine explosive. The colorimetric sensor utilizes the aggregation of creatinine-modified gold nanoparticles (AuNPs), which was caused by nitroguanidine via hydrogen bond interaction between nitroguanidine and creatinine, leading to a color change from red to blue to colorless dependent on the concentration of nitroguanidine. Under optimum sensing concentrations, the absorbance changes of AuNPs at 519 nm were linear with the concentration of nitroguanidine in the range of 15–55 μM with a correlation coefficient of 0.997. The limit of detection of the colorimetric sensor was 1 μM based on the signal-to-noise of three, which has improved by as much as five orders of magnitude as compared with the traditional volumetric method and up to three orders of magnitude as compared with fluorescence approach as well. Moreover, as low as 15 μM of nitroguanidine can be visually detected by the naked eye without instrumentation. The colorimetric sensor also displayed remarkable selectivity to nitroguanidine against other explosives and common inorganic salts. It was robust and can be employed for reliable sensing of spiked nitroguanidine in real water samples with good recovery and accuracy.
研究领域:
分析化学
·
纳米材料科学
·
爆炸物检测
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Jing Yang,Yingdan Cui,Mingyang Chen,Yan Wang,Shijie Xu,Songgu Wu,Jingkang Wang,Junbo Gong
Spherulitic growth, categorized as central multidirectional growth and unidirectional growth via small-angle branching, has increasingly been explored as a method to improve the flowability and bulk density of needle-like crystals. However, the formation of two categories of spherulites in solutions is still unclear. In this work, the formation mechanism of two categories of spherulite was studied in a supercooled nitroguanidine (NQ) aqueous solution with a small amount of gelatin. It is proposed that spherulitic growth depends on the initial morphology of the crystallite, wherein the gelatin concentration, temperature, and initial supersaturation play a vital role. Gelatin can significantly inhibit NQ nucleation, promote branching, and modify the morphology of NQ subunits. At high initial supersaturation and low temperatures, the aspect ratio of the crystal precursor increases and branching is accelerated, so that the lateral faces provide more branching sites than the end faces to promote the unidirectional growth. In comparison, high temperatures promoting the multipoint branching should be mainly responsible for the formation of cauliflower-like spherulites. Furthermore, the bulk densities of the cauliflower-like and compact spherulites of NQ are about triple those of needle-like crystals and their evolutions were observed. Compared with the reported methods, the macromolecule-induced spherulitic growth of NQ without an organic solvent is a green method and will have a bright future for the design and fabrication of other organic spherulites.
研究领域:
晶体工程
·
材料科学
·
物理化学
·
药物制剂
·
软物质物理
✓ 已验证
DOI
高影响因子
TOXICOLOGY AND APPLIED PHARMACOLOGY
·
2022
·
IF 4.46
Suizhi Cheng,Li Che,Qingqing Yang,Rongjing Sun,Yuhong Nie,Haoyue Shi,Yiwen Ding,Li Wang,Zuo Du,Zhenzhong Liu
N -methyl- N′ -nitro- N -nitrosoguanidine (MNNG) is a common alkylating agent , which can be experimentally used as a chemical mutagen and carcinogen, extensively existing in the environment. Folic acid (FA), part of the B group of vitamins, plays an important role in defending against inflammation and reducing the risk of cancers. Nevertheless, there is little research on the protective effects of FA against MNNG-induced esophageal inflammation, and its underlying mechanism still remains elusive. Hence, in the present study, we exposed MNNG to SD rats and esophageal cells to establish the esophageal inflammation models. Our research aims to explore the protective roles of FA against esophageal inflammation induced by MNNG via NF-κB pathway by CCK-8, EdU, RT-qPCR, ELISA , H&E, Western blot . Our results revealed that MNNG decreased the viability of esophageal cells, which was restored under FA intervention. Besides, FA relieved the elevation of IL-6, IL-8 and TNF-α in MNNG-induced esophageal inflammation. Moreover, histopathological analysis showed that epithelial spinous cells proliferated in mucous layer, and inflammatory cells were locally infiltrated in the submucosa after MNNG exposure, while the pathological damage of esophageal tissues was gradually alleviated along with increasing FA doses. And Western blot results demonstrated that FA could relieve the rise of phosphorylated IκBα (p-IκBα) and phosphorylated p65 (p-p65) proteins induced by MNNG. Therefore, it is reasonable to believe that FA has a crucial role in preventing MNNG-induced esophageal inflammation through inhibiting the NF-κB pathway, thereby down-regulating the expressions of IL-6, IL-8 and TNF-α.
研究领域:
药理学
·
毒理学
·
分子生物学
·
病理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CRYSTAL GROWTH
·
2017
·
IF 1.751
Zhilong Luo,Yingdan Cui,Weibing Dong,Qipeng Xu,Gaoxing Zou,Chao Kang,Baohong Hou,Song Chen,Junbo Gong
Nitroguanidine (NQ) is a commonly used explosive, which has been widely used for both civilian and military explosive applications. However, the weak flowability and mechanical performance limit its application. In this work, mechanical performance and thermodynamic stability of NQ crystals were improved by controlling crystal morphologies in the crystallization process. Typical NQ crystals with multiple morphologies and single crystal form were obtained in the presence of additives during the cooling crystallization. The morphology controlled NQ crystals showed higher density, unimodal crystal size distribution and enhanced flowability. The additives showed the inhibitory effect on the nucleation of NQ crystals by in-situ FBRM and PVM determination, and the mechanism was analyzed by means of morphological prediction and molecular simulation. Furthermore, the morphology controlled NQ crystals suggested higher thermodynamic stability according to the calculation of entropy, enthalpy, Gibbs free energy and apparent activation energy on the basis of DSC results.
研究领域:
材料科学
·
化学
·
炸药工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）