COMBUSTION AND FLAME
·
2025
·
IF 6.2
Xiaohui Xue,Tuanwei Xu,Bozhi Hu,Wenke Zhang,Jianzhong Liu
In this study, the agglomeration behavior, gaseous combustion products flow velocity and characteristics of condensed combustion products (CCPs) from a HTPB-based solid propellant were systematically investigated under low-pressure and low-temperature conditions. Furthermore, the underlying mechanisms of these environmental effects were discussed. High-speed microscopic imaging was employed to observe and quantify the agglomeration behavior near the burning surface. Meanwhile, the gaseous combustion product stream velocity in this region was analyzed using both kinetic modeling and theoretical calculations. Experimental results show that when pressure decreases from 1 atm to 0.5 atm, the agglomerate occurrence frequency drops by 90.2 %, the average particle size increases by 14.4 %, and the gaseous product velocity rises by 52.1 %. When reducing the ambient temperature from 20 °C to −40 °C leads to an 18.1 % decrease in agglomerate frequency and a 6.5 % reduction in average particle size, while its effect on gaseous velocity remains inconclusive. Characterization of CCPs reveals that both low pressure and low temperature significantly alter the particle size distribution and reduce the combustion efficiency of solid propellants. Within the experimental conditions of this study (0.3 atm to 1 atm, −40 °C to 20 °C), the impact of pressure changes is greater than that of temperature.
研究领域:
航空航天工程
·
燃烧科学
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材料科学
·
推进技术
✓ 已验证
产品关联
DOI
高影响因子
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
·
2013
·Vol. 39
·期 1
·43-51
·
IF 0.385
Ahmad Nadeem,Khan M. B.,Ma Xiaoyan,Ul-Haq Noaman
Cross-linked and chain-extended polyurethane networks based on hydroxyl-terminated polybutadiene are synthesized by one-step reaction with isophorone diisocyanate. The degree of cross-linking is controlled by varying the triol to diol ratio. Chain extension is optimized by appropriate adjustment in the concentration of the diols. The influence of cross-linking agents and chain-extenders on mechanical properties of cured elastomers is investigated. IR-spectroscopy is employed to observe the curing reaction and inter-segment hydrogen bonding. It is demonstrated that the chain-extended polymer is phase segregated at sub-micron level and registers far better mechanical properties as compared to cross-linked polymer. Incorporation of 1,4 butanediol yields the maximum tensile strength, elongation and modulus. The polymer fabricated with trimethylolpropane is stronger than that of hexanetriol but exhibits lower stretching properties. However, butanediol exhibits superior mechanical properties in comparison to hexanediol. Equilibrium swelling behaviour follows the expected norm; degree of swelling varies inversely with the cross-link density. The chain-extended polymers show reduced degree of swelling due to plausible association between the hard segment domains formed in the micro-phase segregated structures.
研究领域:
高分子材料科学
·
功能高分子
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聚合物化学
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材料力学
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软物质物理
✓ 已验证
DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2026
·
IF 3.6
Xiaoru Wang,Guoxuan Ma,Li Zhou,Lipeng Sang,Shuang Li,Jianru Wang,Bo Yuan,Xueren Wang,Chunxiang Li
Changes in chemical bonds driven by combined thermo-oxidative aging and mechanical loading directly influence the structural integrity of hydroxyl-terminated polybutadiene (HTPB) propellants. Due to uncertainties surrounding the chain scission mechanism of HTPB subjected to thermo-oxidative aging, and the confounding effects of concomitant cross-linking and chain scission on experimental measurements and data interpretation, the present work identifies urethane cross-links as characteristic recognition sites. In situ infrared spectroscopy is utilized to systematically probe chemical bond evolution of HTPB elastomers under static thermo-oxidative aging as well as thermo-oxidative aging coupled with mechanical stress. At the early stage of thermo-oxidative aging, the hydrogen-bond network of urethane groups breaks down first. Bond scission takes place simultaneously across the soft and hard segments of HTPB polyurethane, producing large quantities of amide groups ( CONH ) via oxidative rearrangement. However, secondary cross-linked structures possess limited stability and fully degrade via hydrolysis, oxidation and chain cleavage at the late aging stage. Scission of long molecular chains into shorter segments alters the modulus contributions of chemical cross-linking and physical entanglement. Chemical cross-linking modulus peaks at week six, while physical entanglement modulus maximizes at week eight. When subjected to coupled thermal, humid, oxidative and mechanical fields, stress changes the degradation pathways of HTPB polyurethane. In HTPB soft segments, it mainly causes conformational rearrangement, mechanochemical chain scission and formation of new unsaturated groups. For polyurethane hard segments, stress mainly promotes fatigue degradation and bond scission. This work reveals the microscopic causes behind mechanical property evolution and provides theoretical basis for predicting the service life and optimizing anti-aging formulations of HTPB propellants. Highlights Hydrogen-bond networks and dual-segment chain of HTPB preferentially fracture. Oxidation and chain scission remove secondary cross-links of aged HTPB. Shortened molecular chains alter the modulus of aged HTPB. Mechanical loading alters the thermo-oxidative degradation pathways of HTPB. External loading accelerates bond rupture within hard-segment domains of HTPB.
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Zhoufeng Jiang,Fengqi Zhao,Zhao Qin,Yi Xu,Ying Wang,Yi-Fan Jiang,Ting An,Wengang Qu,Ming Zhang,Hexin Liu,Bingbing Zhang,Lianghua Xiong
AlH3 has gained considerable attention as a fuel additive due to its ability to offer high specific impulse and superior combustion performance. However, few studies have focused on the fragmentation and agglomeration behavior of AlH3. This study investigated the effects of fragmentation of AlH3 and AlH3/PVDF particles on the thermal decomposition, ignition, agglomeration, and combustion of HTPB propellants. Thermal analysis indicated that AlH3 and AlH3/PVDF can accelerate the decomposition of ammonium perchlorate by abundant active sites for the adsorption of the decomposition intermediates. Single-particle combustion uncovered the mechanism behind the directional spray of molten Al from the AlH3 particle and the fragmentation of the AlH3/PVDF particle. The melting of porous Al induces particle shrinkage due to solid–liquid interfacial tension and the structural restoration of the oxide shell, which consequently results in the sealing of cracks in the oxide shell of AlH3. Additionally, the accumulation of internal tensile stress leads to the reopening of these cracks and the directional ejection of the molten Al. The flexible oxide shell contributes to a smaller minimum normalized diameter of the AlH3/PVDF particle, aiding in the generation of internal tensile stress, while the sublimation of AlF3 induced the fragmentation. Synchrotron-based X-ray imaging revealed the formation of aggregates promoted by molten Al, the splitting of AlH3 aggregates due to hydrogen explosion, and the enhanced fragmentation of AlH3/PVDF due to the synergistic effect of hydrogen explosion and the sublimation of AlF3. Compared to raw particles, the CCPs (condensed combustion products) of SP2 propellant display a 48% reduction in average size (D50 = 24.5 μm), whereas there is an over 89% decrease in particle size for the CCPs of SP3 propellant (D50 = 5.14 μm). This study contributes to understanding the fragmentation of AlH3 and AlH3/PVDF upon ignition and combustion, providing valuable insights for the development and optimization of propellants containing AlH3.
研究领域:
材料科学
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燃烧学
·
推进剂工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COMBUSTION SCIENCE AND TECHNOLOGY
·
2025
·
IF 1.5
Wenke Zhang,Jianzhong Liu,Huanhuan Gao,Haitian Gong
To investigate the detailed combustion processes of solid propellant components near the burning surface, this study develops a microscopic ignition and combustion experimental method and establishes a corresponding test system. A high-power microscope and image sensor are employed to continuously record the ignition and combustion of thin-film solid propellants (TFSP, AP/HTPB/Al). By integrating existing theories with image processing techniques, the combustion behavior of AP, Al, and the TFSP as a whole is analyzed in detail. A refined combustion surface model is constructed based on decomposition results, offering theoretical support for ignition combustion modeling and its integration with agglomeration models. Quantitative analysis reveals that reducing AP particle size in TFSP significantly enhances burning rate and combustion surface irregularity. This approach enables the observation of finer combustion behaviors and provides a novel perspective for solid propellant ignition and combustion research.
研究领域:
固体推进剂燃烧
·
微观分析
·
燃烧建模
·
含能材料
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Luyang Wang,Jiahe Li,Changsheng Tang,Pengxiang Li,Yulin Yang,Debin Xia,Jian Zhang,Ping Wang,Kaifeng Lin
Aluminum–lithium (Al Li) alloy powders exhibiting the micro–explosion phenomenon are promising energetic additives for solid propellants. However, their high surface reactivity, particularly due to lithium (Li), leads to poor compatibility with binder components, thereby hindering practical application. Importantly, low−temperature reaction conditions slowed the reaction rate, helping to preserve the active components of Al 5Li powder during its modification with dichlorodimethylsilane (DCDMS) via a Li–induced low−temperature Wurtz–type reaction, which resulted in in–situ polymerization and formation of LiCl. Residual Si Cl groups reacted with surface hydroxyls, generating trace HCl that removed native passivation layers (e.g., Li₂CO₃) and produced additional LiCl, while low–temperature enhanced DCDMS adsorption and limited surface species consumption, promoting formation of a dense chlorosilane coating encapsulating part of the LiCl. The modified Al–5Li@DCDMS powders showed good compatibility with hydroxyl–terminated polybutadiene (HTPB) and, compared with conventional Al–based HTPB propellants, exhibited pronounced micro–explosion behavior, with a 6.84 % higher burning rate and a 43.90 % shorter ignition delay. This work offers a viable surface passivation strategy and demonstrates the application potential of Al Li alloy powders in advanced solid propellant systems.
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产品关联
DOI
高影响因子
Defence Technology
·
2026
·
IF 6.4
Kan Xie,Yiyang Wang,Zijie Zhao,Jingyu Lei,Sulan Yang,Bin Tian
The dense oxide layer on the surface of aluminum (Al) particles is recognized as a major limitation to their combustion efficiency in solid propellants. Metal fluorides have emerged as promising combustion modifiers capable of enhancing Al reactivity through a catalytic-activation synergy. However, the systematic influence of NiF 2 content on this process remains poorly understood. In this work, the effect of NiF 2 content on the combustion performance of Al/AP composite fuels and hydroxyl-terminated polybutadiene (HTPB)-based propellants was systematically investigated. A series of composites and propellants with varying NiF 2 loadings were prepared and evaluated using an oxygen bomb calorimeter, thermal analysis, high-speed photography, and product characterization. The optimal NiF 2 content was determined to be 6 wt%, at which the composite fuel achieved a maximum reaction heat of 9357.62 J/g, corresponding to a 12.3% increase relative to the unmodified sample. Thermal analysis revealed that an appropriate amount of NiF 2 leads to the merging of the low- and high-temperature decomposition peaks of AP and the concentration of the exothermic event, indicative of a synergistic catalytic effect; excessive addition, in contrast, was found to suppress heat release. In propellant combustion, the SP-2 sample containing 2 wt% NiF 2 exhibited the most pronounced pressure-dependent burning-rate increase, with a maximum increase of 26.9% over the pressure range of 1.5–2.5 MPa. Product analysis further demonstrated that the condensed combustion products (CCPs) of SP-2 contain a higher proportion of Al 2 O 3 , exhibit a significantly reduced and multimodal particle size distribution with abundant submicron particles, and feature detectable AlN, confirming that NiF 2 effectively inhibits molten Al agglomeration and promotes combustion completeness. Therefore, the optimal working window of NiF 2 in the Al/AP system is identified, and its synergistic oxide-layer erosion and catalytic decomposition mechanism is elucidated, providing a key basis for the development of high-performance Al-based propellants.
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2018
·Vol. 135
·期 18
·46222
·
IF 1.901
Xia Gao,Tianbo Zhao,Guan Luo,Baohui Zheng,Hui Huang,Rui Ma,Xue Han,Yuqiao Chai
Polystyrene (PS) microencapsulated paraffin wax (MePW) and PS–SiO 2 MePW were used to improve the form-stability of PW in hydroxyl-terminated polybutadiene-derived polyurethane (HTPB) binder. HTPB matrix containing different contents of PS MePW, PS–SiO 2 MePW, and PW were prepared. The chemical composition, crystallinity, microstructure, heat capacities, thermal stabilities, thermal reliabilities, leakage, and mechanical properties of the composites were compared using Fourier transforms infrared spectroscope, X-ray diffractometer, scanning electronic microscope, differential scanning calorimeter, thermo-gravimetric analyzer, thermal cycling test, leaking test, compression, and tensile tests, respectively. The results showed that the MePW/PW/HTPB composites were prepared without chemical reaction. The thermal stability and mechanical properties of PS–SiO 2 MePW/PW/HTPB increased more dramatically than that of PS MePW/PW/HTPB. With the increasing contents of MePWs, the PW leakage of the composites decreased, especially for PS MePW/PW/HTPB. Consequently, the MePW/PW/HTPB composites possess a potential application for PW-based polymer-bonded explosive system. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46222.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Baoyun Ye,Hongyi Chen,Binhao Shen,Chang Liu,Chongwei An,Jingyu Wang,Yong Zhang
In this work, a novel CuO-based nanocomposite was successfully prepared by hydrothermal method . The results of FT-IR, XRD , XPS and SEM indicated that the nano CuO was successfully loaded on GO/MoS 2 sheets. The catalytic ability of the CuO-based composite was researched by the AP thermal decomposition behavior and the combustion behavior of AP/HTPB. The CuO-based composite could significantly enhance the AP thermal decomposition performance through decreasing the activation energy of AP during the thermal decomposition process. Especially for CuO(90)@MG(10), the AP thermal decomposition temperature was reduced from 437.5 to 334.9 °C and the heat release increased from 396.7 to 1576.8 J/g by adding 4% of the CuO-based nanocomposite. After adding the CuO-based nanocomposite, the ignition delay time of AP/HTPB solid propellant decreased obviously from 0.346 s to 0.109 s with a higher flame height and a stronger flame brightness during the combustion process, indicating that the CuO-based nanocomposite could effectively promote the combustion behavior of AP/HTPB composite solid propellant. In summary, the CuO-based nanocomposite could be applied as an excellent catalyst for improving AP thermal decomposition and a combustion catalyst for AP-based composite solid propellants.
研究领域:
材料科学
·
推进剂研究
✓ 已验证
产品关联
DOI
高影响因子
CELLULOSE
·
2021
·Vol. 28
·期 13
·8671-8691
·
IF 5.044
Zhao Ningning,Ma Haixia,Yao Ergang,Yu Zhong,An Ting,Zhao Fengqi,Yu Xiaojiao
Al/CuO nanothermites have displayed unique catalytic activities in accelerating the thermolysis of nitrocellulose (NC) and combustion characteristics of AP/HTPB propellant depending on the morphology of CuO. The kinetic triplet of NC-based composites was determined by multi- isoconversional methods, whereas the reaction models were reconstructed by employing a modified Šesták–Berggren equation based on the combined kinetic analysis. DSC and TG-FTIR results revealed that CuO and Al/CuO play crucial roles in accelerating the dissociation of –O–NO 2 bond and the coacervate phase to change the pyrolysis mechanism of NC from an autocatalytic reaction to a modified n -th order reaction model. It was also demonstrated that nanothermites were provided with a low starting temperature of pyrolysis, reduced exothermic peak temperature, low activation energy, and high total weight loss, confirming their better catalytic activity than their corresponding CuO, of which Al/CuO nanothermite, containing the gypsophila paniculata-like CuO, performs the best. Further, the shape of CuO was found to be significant in enhancing the burning rate of AP/HTPB propellant containing thermites, with the gypsophila paniculata-like presenting the best catalytic effect (43% improvement). Hence, introducing well-defined nanostructures is a promising way to improve the pyrolysis and combustion of energetic materials.
研究领域:
含能材料
·
推进剂化学
·
纳米催化
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热分析
·
燃烧科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Lianpeng Cui,Jie Zhang,Xi Chen,Honghong Qin,Kangzhen Xu,Xiaolong Fu,Suhang Chen
Hybrid rockets present an attractive option for small, low-cost launch vehicles, space tourism and exploration, owing to their features of intelligent remote control of thrust and switch, rapid response capabilities, cost-effectiveness, environmental friendliness. However, it suffers from low regression rate ( r f ) of solid fuels relating to difficult vaporization of fuel and low heat feedback from diffusion-dominated combustion. Herein, high‑nitrogen energetic compounds (HNEC) sodium azotetrazole (STZ) and 4,4′,6,6′-tetraazido-1,3,5-triazine (TAHT) were employed into hydroxyl-terminated polybutadiene (HTPB) fuels to amplify its r f and thermal decomposition with minimizing formulation complexity, respectively. Here the STZ was prepared by one-step oxidation coupled with spray-drying and TAHT was prepared by two-step method of hydrazine uncoupling and diazotization. The combustion regression process of fuels at oxygen flow were measured at hybrid propellent combustion platform to determine the r f and micro-explosion combustion. The r f of the 5 wt% STZ and TAHT formulation reached 2.84 and 3.46 mm/s at an oxygen mass flux ( G ox ) of 200 kg/m 2 ·s, increasing by 300.00 % and 387.32 % compared to pure HTPB. Upon the cessation of combustion, the scanning electron microscope (SEM) image of the HNEC material showed a porous layer structure, ensuring sufficient contact between fuel and oxygen and accelerating r f . Furthermore, HNEC had a catalytic decomposition effect on HTPB via the differential scanning calorimetry (DSC) tests, where the decomposition end temperature ( T end ) of the heat classification was maximum advanced by 71.03 (5 wt% STZ) and 20.64 °C (5 wt% TAHT). Above analysis results indicate that cost-effective HNEC overcome the thermal feedback limitations of conventional fuels through a micro-explosion and catalyze synergistic mechanism, as well will offer a novel direction for combustion rate control in hybrid rocket propulsion.
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产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2025
·
IF 6.3
Hongqi Nie,Ruixuan Xu,Xin Li,Yuruizhi Lin,Suhang Chen,Kangzhen Xu,Jia-Rong Zhang,Qi-Long Yan
The combustion characteristics and energy output properties of solid propellants play a decisive role in rocket engine and propulsion system performance. Particularly for HTPB propellant systems incorporating CL-20 as the high-energy oxidizer, achieving wide-range burn rate regulation and maintaining low pressure exponents constitute fundamental requirements for practical implementation. Through advanced interfacial control methodology, this study successfully constructed two types of aluminum/oxidizer integrated composites (Al@AP and Al@CL-20), while employing precise catalysis to accurately distribute C 3 N 4 burn rate modifiers within the target oxidizer. This innovative approach has demonstrated significant enhancement in aluminum combustion efficiency within the composite propellant system. The strategic incorporation of C 3 N 4 , coupled with the optimized interfacial architecture between fuel and oxidizer components, establishes a new paradigm for performance modulation in solid propellant formulations. Thermal analysis (DSC/TGA) results reveal that both Al@AP/CN and Al@CL-20/CN composites exhibit concentrated exothermic characteristics, yet demonstrate fundamentally distinct heat release profiles. By strategically exploiting these differential energy release features, propellant formulations with tailored interfacial compositions and precisely engineered catalytic sites were developed. The modified propellants displayed markedly different combustion behaviors: the Al@CL-20/CN-based formulation achieved a 33% reduction in pressure exponent ( n =0.18) with significantly enhanced low-pressure burning rates, while the Al@AP/CN-modified system maintained ultra-low burning rates (<5 mm·s -1 ) but with high combustion efficiency across broad pressure ranges with an exceptionally low pressure exponent of 0.23. Complementary analysis of condensed combustion products (CCPs) confirmed substantial improvements in combustion completeness, showing a 78% reduction in micron-sized aluminum agglomerates and significantly refined CCPs particle size distribution. These findings collectively demonstrate that the synergistic combination of interfacial modification and precision catalysis effectively optimizes aluminum combustion efficiency and tunability of burn rate of high-energy HTPB propellants.
研究领域:
航空航天工程
·
推进系统
·
材料科学
·
含能材料
·
燃烧化学
✓ 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）