JOURNAL OF BIOMATERIALS APPLICATIONS
·
2016
·
IF 1.988
Feng Xu,Jing-Wen Xu,Yan-Ling Luo
pH-Sensitive poly(methacrylic acid)-block-hydroxyl-terminated polybutadiene-block-poly(methacrylic acid) (PMAA-b-HTPB-b-PMAA) was synthesized and then hydrogenated in this work. The chain structure, phase behavior and thermal properties were characterized by 1H NMR, FTIR, XRD, DSC, TGA, etc., and the physicochemical and biomedical properties were investigated via fluorescence spectroscopy, TEM, DLS, loading and release of drug and MTT, and so on. The experimental results indicated that the hydrogenation led to the change in the chain aggregate structure of hydrophobic HTPB blocks and the formation of more stable spherical core-shell micelle aggregates, and the critical micelle concentration decreased from 41.8 mg L−1 before hydrogenation to 4.4 mg L−1 after hydrogenation. The hydrogenated block copolymer micelle aggregates exhibited pH-triggered response, and could entrap twice as much hydrophobic drug as the unhydrided counterparts and the encapsulation efficiency was significantly improved, which makes them fine to meet the requirements for drug carriers. Therefore, the hydrogenated PMAA-b-HTPB-b-PMAA copolymer micelles as drug target release carriers can be well used in the field of prevention and treatment of cancers.
研究领域:
材料科学
·
生物医学工程
·
药学
✓ 已验证
DOI
PubMed
高影响因子
COMBUSTION AND FLAME
·
2024
·
IF 5.8
Jiabao Zhu,Shuo Wang,Weiqiang Xiong,Jun Wang,Xiaodong Li,Meishuai Zou
Aluminum-lithium alloy powder exhibits better thermal properties and combustion performances than aluminum , thus showing promising applications in the field of energetic materials such as explosives and propellants. However, the high activity of lithium also raises issues of stability and compatibility with propellant components, deteriorating the powder's overall performance. In this study, a facile coating method is presented using 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PFOTS) as a surfactant to coat hydroxyl‑terminated polybutadiene (HTPB) on the surface of Al-5Li powder, forming the core-shell composite Al-5Li@HTPB. The microstructure and chemical composition characterized by SEM, EDS , XPS , FT-IR, and nano-CT demonstrated that a uniform and dense layer was successfully coated on the surface. The thermal analysis results showed a significant improvement in the thermal properties and stability compared to pure Al-5Li. In addition, ignition tests were conducted, and the results showed that Al-5Li@HTPB could reduce the ignition delay time and significantly reduce agglomeration. Overall, our strategy provides a novel method to solve the stability issues of Al-Li powders and simultaneously enhance combustion performance.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2024
·
IF 5.8
Ming Zhang,Fengqi Zhao,Jiankan Zhang,Ying Wang,Xueli Chen,Ting An,Zhao Qin,Haixia Hao
Graphene iron tannate and graphene iron gallate nanocomposites (G-D-Fe and G-M-Fe) were designed, synthesized and characterized to deal with the performance requirement of AP-HTPB propellent. Effects of the G-D-Fe and G-M-Fe on the thermal decomposition of AP, laser ignition, combustion and safety characteristics of AP-HTPB propellant were explored. By taking Catocene as the benchmark (156.80 mJ), the G-D-Fe improves the safety performance of propellant, and the ignition energy ( E 50 ) is increased by 17.25 mJ. Besides, the G-D-Fe and G-M-Fe have positive effects on enhancing the burning rate and the reducing the pressure exponent of propellant, and the influence of G-D-Fe is more significant. The burning rate enhances from 13.87 to 16.92 mm·s −1 at 15 MPa and the pressure exponent reduces from 0.47 to 0.32 in 4∼15 MPa after the introduction of G-D-Fe. The catalytic mechanism of G-D-Fe were analyzed on the basis of flame morphology, combustion wave structure, in-situ FTIR and gas-phase FTIR-MS. The outstanding catalytic property of G-D-Fe is due to its promotion effect on AP pyrolysis and the formation of stable products, which is conductive to the intense reactions of gas products and the thermal transmission between burning surface and gas phase, and reflecting in the significant enhanced burning rate.
研究领域:
材料科学
·
燃烧学
·
推进剂工程
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2013
·
IF 3.554
Yan-Ling Luo,Xiao-Li Yang,Feng Xu,Ya-Shao Chen,Bin Zhang
Two kinds of thermo-sensitive poly(N-isoproplacrylamide) (PNIPAM) block copolymers, AB 4 four-armed star multiblock and linear triblock copolymers, were synthesized by ATRP with hydroxyl-terminated polybutadiene (HTPB) as central blocks, and characterization was performed by 1 H NMR, FT-IR and SEC . The multiblock copolymers could spontaneously assemble into more regular spherical core–shell nanoscale micelles than the linear triblock copolymer. The physicochemical properties were detected by a surface tension technique, nano particle analyzer, TEM, DLS and UV–vis measurements. The multiblock copolymer micelles had lower critical micelle concentration than the linear counterpart, TEM size from 100 to 120 nm and the hydrodynamic diameters below 150 nm. The micelles exhibited thermo-dependent size change, with low critical solution temperature about 33–35 °C. The characteristic parameters were affected by the composition ratios, length of PNIPAM blocks and molecular architectures. The camptothecin release demonstrated that the drug release was thermo-responsive, accompanied by the temperature-induced structural changes of the micelles. MTT assays were performed to evaluate the biocompatibility or cytotoxicity of the prepared copolymer micelles.
研究领域:
高分子化学
·
药物传递系统
·
生物材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACTA ASTRONAUTICA
·
2024
·
IF 3.1
Yi-min Luo,Teng Ma,Hong-wei Zhao,Nian Yang,Sen Xu,Wen-fang Zheng
Slow-burn propellants are crucial for aerospace advancement. This study focuses on the development of slow-burn propellants by replacing a small amount of AP (3–9 %) with various amine-based burning rate suppressants (BRSs). The consistency between thermal analysis and combustion test results indicates a direct link between the main exothermic decomposition process and combustion performance, with changes in onset temperature positively correlated with decreases in combustion parameters. Upon adding 3 % oxamide, the onset temperature of the main decomposition peak in DSC shifted backward by 16.2 °C, significantly higher than the formulations containing ammonium sulfate at 2.6 °C and ammonium oxalate at −0.8 °C. As the content of oxamide further increased from 3 to 9 %, the ignition delay time increased simultaneously by 0.300–1.638 s, atmospheric burning rate decreased by 14.01–45.45 %. These values represent the maximum among formulations with the same content of the BRSs, mainly attributed to its higher heat absorption capacity .
研究领域:
航空航天工程
·
材料科学
✓ 已验证
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Hongsheng Yu,Suhang Chen,Xiaodong Yu,Wei Zhang,Christian Paravan,Luigi T. DeLuca,Ruiqi Shen
The slow regression rate induced by the difficulty of pyrolysis has limited the practical application of hydroxyl-terminated polybutadiene (HTPB)-based fuels for hybrid rocket propulsion. A possible strategy is the use of suitable transition metal elements promoting polymer matrix thermal decomposition of fuels. This paper investigates the effects of nickel acetylacetonate, Ni(acac) 2 , on the thermal stability and combustion of HTPB-based fuel formulations. The presented experimental results show that the addition of Ni(acac) 2 can intensely decrease the thermal stability of HTPB thus enhancing the solid fuel regression rate even at a small additive mass fraction: under an oxygen mass flux of 50 kg/m 2 s, HTPB + 5 wt% Ni(acac) 2 shows a 25.5% increase over the non-loaded baseline. Kinetics analyses reveal that the catalytic effect is mainly induced by the Ni 2+ in Ni(acac) 2 at the early stage of decomposition, and by the NiO produced from the oxidative decomposition of Ni(acac) 2 in the fuel final degradation stage. On the other hand, the addition of Ni(acac) 2 decreases the combustion heat of HTPB-based fuels significantly and implies the accumulation of its decomposition products (much metal Ni, moderate elemental C, and a little NiO.) at the fuel regressing surface. Eventually, when the content of Ni(acac) 2 exceeds 5 wt%, the growth of regression rate slows down rapidly, and a performance detriment occurs at 40 wt%. This study verifies the catalytic effect of Ni(acac) 2 on polymer matrix for HTPB based fuels showing the attractive regression rate performance of this additive.
研究领域:
推进剂化学
·
燃烧学
·
高分子材料科学
·
航天动力工程
·
催化化学
✓ 已验证
DOI
高影响因子
Materials Today Communications
·
2024
·
IF 3.7
Jiahe Li,Fang Du,Changsheng Tang,Luyang Wang,Yulin Yang,Debin Xia,Jian Zhang,Bowen Tao,Ping Wang,Kaifeng Lin
Solid propellant containing Al-Li particles has attracted much attention because of the high combustion efficiency and effective absorption of HCl in burning tail smoke. However, the highly reactive Li has limited the application due to the lower stability and compatibility with HTPB. In this study, the chemically stable Al-5Li particles were fabricated by a thin organic layer, which was used by the dodecyltrimethoxysilane (DTMS) or 1H,1H,2H,2H-perfluorooctyltrimethoxysilane (FTMS) with the site-selective coating of active Al and Li. Meanwhile, the Li-F coordination bond also provides a deeper protection with the decrease of hygroscopicity with 39.08 % mass variation through the XPS test of Al-5Li@FTMS. The Al-5Li@FTMS and Al-5Li@DTMS particles had good stability and compatibility with HTPB to 1 or 2 degree and none pores or cracks on the cross section of propellant. Note here that the Al-5Li@FTMS and Al-5Li@DTMS propellants exhibited a shorter ignition delay time, higher peak flame temperature and smaller particle size of residue corresponded to Al propellant. Meanwhile, the burning rates of propellants had increased by 2.80 % and 0.93 %. Thus, the coating of FTMS is better than that of DTMS from the stability and combustibility. The micro-explosion characteristic of Al-5Li particles would provide higher combustion efficiency and performance. The feasible fabrication method would provide an relevant guidance for the stability and combustibility of alloy powders in solid propellant.
研究领域:
材料科学
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energetic Materials
·
2024
·
IF 1.7
Jing-Si Sun,Hong-Jie Li,Jing-Zhuo Gao,Ting-Run Li,Ze-Cheng Hu,Rui-Feng Wu,Ying Wang
Organic-inorganic double-coated aluminum nanopowders (HTPB/Cu/nAl) were synthesized using a one-pot method. The morphology and structure were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). The analysis revealed that Cu particles were uniformly dispersed around the nAl core, while HTPB formed a coating on the Cu/nAl surface. The thermal oxidation kinetics and catalytic effects on ammonium perchlorate (AP) were investigated through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results indicated a 9% increase in the active aluminum content of the double-coated nanopowders compared to uncoated nAl, and a reduction in the average activation energy for thermal oxidation from 297.75 kJ·mol-1 to 218.85 kJ·mol-1. The HTPB coating enhanced the friction and impact sensitivity of the Cu/nAl particles. Adding 5% HTPB/Cu/nAl to AP advanced the low- and high-temperature decomposition peaks by 5°C and 40°C, respectively, while reducing the activation energy of AP from 85.61 kJ·mol-1 to 79.79 kJ·mol-1. This addition significantly influenced the thermal decomposition of AP, improving combustion efficiency and enhancing compatibility within composite propellant formulations.
研究领域:
材料科学
·
燃烧与推进
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Zikangping Wang,Zhi-Hua Xue,Ke-Juan Meng,Xue-Xue Zhang,Qi-Long Yan
Two types of qy-HMX (insensitive HMX with improved energy density, numbered 1 and 2) have been used and studied as an ingredient of HTPB-based composite propellants (CPs), and the decomposition and combustion performances have been investigated. It has been shown that the main exothermic peak temperature of blank CPs containing 21 wt% of qy-HMX-1 is 258.9 °C, which is 4.7 °C higher than that of HMX-containing one, indicating improved thermostability. The corresponding heat of explosion for blank qy-HMX-2-based CPs was measured to be 5830 J∙g −1 , which is 300 J∙g −1 higher than that of HMX-based one. Interestingly, the qy-HMX-2-based CPs has higher energy density than corresponding CL-20-based ones, but it has much lower burn rate under the same pressure, e.g. 4.38 mm∙s −1 at 3 MPa for the former vs. 9.03 mm∙s −1 for the latter. Under the effect of typical conventional catalysts such as nano-CuO and nano-Fe 2 O 3 , the qy-HMX-1-based CPs showed increased heat of explosion and higher burn rate. In addition, the particle sizes of condensed combustion products (CCPs) of CPs containing qy-HMX-2 are much smaller than that of HMX-based one, where the Al 4 C 3 was produced as its unique CCPs ingredient.
研究领域:
材料科学
·
燃烧与爆炸学
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2025
·Vol. 10
·期 21
·e06152
·
IF 2
Shuai Wang,BingXi Song,Ze Su,Yijie Cai,Long Liu,Chang Su,Yanqiang Zhang
Graphical A new ionic liquid plasticizer [NTAZ][NTf 2 ] was synthesized. Compared with the traditional plasticizer DOA, [NTAZ][NTf 2 ] can significantly improve the energy of the propellant formulation. Energetic plasticizer is an important means to improve the energy performance of solid propellants, but there is no suitable energetic plasticizer for HTPB/TDI system. In this work, a nitrate-functionalized ionic liquid plasticizer of 1-Methyl-4-(8-(Nitrooxy)octyl)-1,2,4-triazolium bis((trifluoromethyl)sulfonyl)imide ([NTAZ][NTf 2 ]) was synthesized, and the energy was increased by the combination of nitrate functional group and 1,2,4-triazole cation. The hydrogen bond between the anion and the cation and HTPB achieves a good plasticizing effect. When 6% [NTAZ][NTf 2 ] was added to HTPB/TDI system, the glass transition temperature decreased from −63.41 °C to −64.84 °C, the tensile strength increased from 0.52 MPa to 0.79 MPa, and the storage modulus increased from 64.02 MPa to 110.32 MPa. When 4% DOA is replaced by the same amount of [NTAZ][NTf 2 ] in the HTPB formulation system, the specific impulse is increased from 261.0 s to 271.4 s. This study will guide the design and application of new energetic solid propellant plasticisers, both theoretically and experimentally.
研究领域:
材料科学
·
推进剂化学
✓ 已验证
产品关联
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2020
·
IF 1.568
Islam K Boshra,Guo Lin,Ahmed Elbeih
The crosslinking agent is a vital key which affects the mechanical properties of composite solid rocket propellants (CSRPs). Under this scheme, the effect of crosslinking mixtures (CMs) based on trimethylolpropane (TMP) as a triol crosslinker and butanediol (BD) as a chain extender on CSRPs based on hydroxyl-terminated polybutadiene was investigated. A series of 27 propellant compositions was formulated to study the mechanical properties of the prepared CSRPs. The effect of changing the weight ratio of TMP to BD in the CM was studied. In addition, the influence of increasing the percentage of CM (from 0% to 0.5%) in the prepared samples was investigated. Also, the effect of the CM on CSRPs containing different curing ratio of NCO/OH = 0.7, 0.75, and 0.8 was studied to generate the largest possible strain-ability with high strength over different levels of curing conditions. The mechanical characteristics (tensile strength and strain) of the prepared CSRPs have been measured and plotted versus CM content, NCO/OH and TMP:BD ratio. Generally, the addition of CM leads to a remarkable enhancement in the propellant mechanical properties. Samples containing TMP:BD (2:1) provide the highest strength while samples containing TMP:BD (1:2) show the highest strain over all the NCO/OH ratios. Formulations with TMP:BD (1:1) give high strength with moderate strain. Variation in CM content has a remarkable influence on the mechanical properties of CSRPs. A wide range of tensile strength and strain were obtained from this study to offer variety of results suitable for different applications in the CSRPs technology.
研究领域:
材料科学
·
航空航天工程
·
推进系统
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2024
·
IF 5.8
Ruixuan Xu,Xin Li,Zhihua Xue,Danfeng Yang,Suhang Chen,Kangzhen Xu,Qi-Long Yan,Hongqi Nie
In this work, the combustion enhancement and agglomeration inhibition of HTPB-based composite propellants have been achieved by incorporation of Al@AP composites containing a nitrogen-rich compound 4,4′,6,6′-tetra(hydrazino)hydrazo-1,3,5-triazine (THHT) as a burning rate modifier. The thermal reactivity and decomposition behavior of Al@AP/THHT composites were studied using DSC/TGA/FT-IR techniques. These composites showed a greater heat release with lower decomposition peak temperature. The propellant formulations could be well tuned by adjusting the mutual distance between Al/AP and THHT crystals. The results suggest that the inclusion of Al@AP/THHT in solid propellants would lead to enhanced energy release, with the value of explosion heat increased from 5632.0 J g -1 to 5971 J g -1 (+6.0 %), the ignition delay time decreased from 105 ms to 79 ms (-24.8 %) and the flame radiation intensity maximum raised from 2199 to 1988 (+10.6 %). The modified propellants are featured with a chemical reaction-dependent flame propagation rate at lower pressure range (1∼10 MPa) and a pressure-controlled process over 10 MPa. The burning rate of propellant at 1 MPa can be increased from 6.1 mm s -1 to 7.0 mm s -1 (+14.8 %) by the inclusion of Al@AP/THHT. The pressure exponent of modified propellants was reduced from 0.48 to 0.33 in pressure range 1∼15 MPa, which is mainly attributed to the activation of Al@AP at lower pressure. Furthermore, the inhibition of Al agglomeration was found once it was coated with AP. The characterizations on condensed combustion products (CCPs) demonstrated an enhancement in combustion efficiency due to an increased content of Al 2 O 3 , accompanied with a remarkable reduction of mean size from 14.0 μm to 1.3 μm (-90.7 %) and a rise in the proportion of nano-/micron-sized particles. The overall effects of Al@AP interfacial control and precise catalysis of THHT on the energy release and combustion of propellants were identified and the primitive combustion mechanisms are proposed.
研究领域:
推进剂化学
·
燃烧科学
✓ 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）