含纳米级铝粉的复合炸药研究

铝粉的颗粒尺寸对含铝炸药的爆轰性能有显著影响，在以RDX为主体的粘结炸药中，加入20％粒径为50nm的超细铝粉，得到的新型复合炸药，其爆轰性能及作功能力明显高于含20％粒径为5μm和50μm的复合炸药。     

含铝硝酸异丙酯的热分解性能(英文)

制备了硝酸异丙酯(IPN)与铝粉质量比分别为2∶1、1∶13.7的两种含铝硝酸异丙酯(IPN)样品,用DSC方法研究了其热分解行为。采用Setsak-Satave方法和Kissinger公式计算了两种样品的最可几机理函数及热分解动力学参数。结果表明,含铝IPN样品分解过程的峰温与纯IPN相比均较低,两种样品的最可几函数均为f(α)=α1/2,不随铝粉含量的变化而发生变化。加入铝粉后,IPN分解的活化能和指前因子均变小;IPN与铝粉质量比为1∶13.7的含铝IPN样品的热分解动力学参数值和分解速率均高于质量比为2∶1的含铝IPN样品。     

Al粉对炸药爆炸加速能力的影响

采用电探针法测量了RDX基含铝炸药爆炸驱动金属薄片的速度变化,分析了铝粉含量对炸药爆炸加速能力的影响。结果表明,炸药爆炸对金属薄片的加速能力受配方中铝粉的反应比例影响;金属薄片的加速过程分速度增长和速度减小两个阶段;金属薄片达到最大速度的距离与铝粉的含量有关,随着铝粉含量的增加,达到最大速度的距离有所增加,该距离在40~60mm。铝粉含量对炸药爆炸加速能力的贡献有一最佳值,对于RDX基含铝炸药,其值约为15%。     

5,5′-偶氮四唑过渡金属含能配合物对RDX和HMX热分解行为的影响

用DSC研究了5种5,5′-偶氮四唑过渡金属配合物MATZ(H2O)n(M=Mn,Ni,Zn,n=6;M=Co,Pb,n=3;ATZ=5,5′-偶氮四唑离子)对RDX和HMX热分解行为的影响。用分解峰温、热爆炸临界温度等特征参数评价了含配合物的二元混合物与纯组分的热分解行为。结果表明,配合物对RDX的影响大于对HMX的。含配合物的二元混合物的热分解行为与纯组分的热分解行为类似,配合物的分解影响了RDX和HMX的热分解特征参数。     

RDX和铝含量对RDX基含铝炸药热爆发温度的影响

通过热爆发延滞期试验测定了含铝炸药的5s延滞期热爆发温度Tb,研究了RDX和铝粉含量对热爆发温度的影响.结果表明,随着RDX含量的增加,Tb先下降后升高,获得了描述Tb与RDX和铝粉含量关系的线性经验方程.认为在热爆发试验中体系是从含能材料热分解和加热介质两个途径获得能量(热量),前者与含能反应物的含量有关,后者与体系...     

超重力辅助溶剂-反溶剂重结晶法制备亚微米级RDX

为了获得粒径分布均匀的细化RDX,在超重力反应器中,以丙酮-水作为溶剂-反溶剂重结晶体系,添加聚乙烯吡咯烷酮(PVP)作为表面活性剂,制备了亚微米级RDX。研究了RDX溶液浓度、PVP含量以及超重力反应器转速对RDX形貌和尺寸的影响,获得最优工艺条件,利用SEM、XRD和FT-IR对其形貌、晶体结构和分子结构进行了表征,并采用DSC研究了RDX的热分解过程。结果表明,在RDX溶液浓度为0.04g/mL、PVP浓度为0.2g/L、超重力反应器转速为1500r/min时,制备了平均粒径为0.54μm的亚微米级RDX,细化处理未改变RDX的晶型;与原料RDX相比,亚微米级RDX的分解峰温提前了1.2℃,热分解活化能从180~250kJ/mol降至约150kJ/mol。     

硼金属化RDX基炸药的热行为

采用热重(TG-DTG)及高压差示扫描量热(PDSC)技术,考察了含硼金属化RDX基炸药的热行为。研究了不同金属组分对金属化炸药热分解性能的影响,计算获得热分解的动力学参数表观活化能及指前因子。结果表明,RDX分解及其分解产物能"活化"硼粉,使之在高温下更易被氧化或氮化,而RDX对Al粉或Mg粉氧化反应的影响相对较小;B、Al和Mg金属粉的加入导致RDX的热分解反应表观活化能和速率降低,DSC(PDSC)和DTG峰温滞后,DSC的量热值下降。     

纳米Bi2O3·SnO2的制备及对RDX热分解特性的影响

为了研究纳米Bi2O3*SnO2对推进剂燃烧的催化作用,以BiCl3和SnCl4*5H2O为原料,采用共沉淀法制备出纳米Bi2O3*SnO2粉体,产物的粒径约为5 nm.用DSC测试了纳米Bi2O3*SnO2对RDX热分解特性的影响.结果表明,纳米Bi2O3*SnO2对RDX热分解有明显的催化效果,使RDX的分解峰温前移了13.7 ℃,放热量增加665 J/g,活化能降低49.42 kJ/mol.     

RDX/GAP纳米复合含能材料的制备及热性能

以聚叠氮缩水甘油醚(GAP)和六亚甲基二异氰酸酯(HDI)为原料,二月桂酸二丁基锡(T-12)为催化剂,通过溶胶-凝胶法及溶液结晶法制备了RDX/GAP纳米复合含能材料。用BET法、X-射线粉末衍射、扫描电镜对其结构进行了表征,用TG/DSC分析了其热性能。结果表明,RDX/GAP纳米复合含能材料具有纳米网孔结构,与GAP干凝胶相比,其比表面积下降,平均粒径为20~50nm。RDX/GAP纳米复合含能材料中的RDX热分解峰温明显提前,分解热显著高于RDX/GAP物理共混物的分解热。     

纳米铝对RDX基炸药水下爆炸能量的影响

为了探索纳米铝对RDX基压装炸药的水下爆炸能量的影响,测试了含纳米铝、微米铝、以及纳米铝和微米铝级配的RDX基炸药水下爆炸能量,分析了其水下爆炸能量的变化规律。结果表明,RDX基压装炸药中,当单独使用纳米铝或微米铝时,纳米铝对炸药水下爆炸总能量的提高不如微米铝;当铝粉总质量分数为30%,且纳米铝和微米铝的质量比为1∶2时,水下爆炸总能量比单独使用微米铝时提高7%,说明纳米铝和微米铝合理级配能够提高铝粉的能量释放效率。当铝粉总质量分数为35%时,即使采用级配也无法提高含铝炸药的水下爆炸能量。     

Research on the Combustion Properties of Propellants with Low Content of Nano Metal Powders

A comparison of various experimental results for combustionrelated properties evaluation, including burning rates, deflagration heat, flame structures and thermal decomposition properties, of AP/RDX/Al/HTPB composite propellants containing nano metal powders is presented. The thermal behavior of n‐Al (nano grain size aluminum) and g‐Al (general grain size aluminum i.e., 10 μm) heated in air was also investigated by thermogravimetry. The burning rates results indicate that the usage of bimodal aluminum distribution with the ratio around 4 : 1 of n‐Al to g‐Al or the addition of 2% nano nickel powders (n‐Ni) will improve the burning behavior of the propellant, while the usage of grading aluminum powders with the ratio 1 : 1 of n‐Al to g‐Al will impair the combustion of the propellant. Results show that n‐Al and n‐Ni both have a lower heating capacity, lower ignition threshold and shorter combustion time than g‐Al. In addition n‐Al is inclined to burn in single particle form. And the thermal analysis results show that n‐Ni can catalyze the thermal decomposition of AP in the propellant. The results also confirm the high reactivity of n‐Al, which will lead to a lower reaction temperature and rather higher degree of reaction ratio as compared with g‐Al in air. All these factors will influence the combustion of propellants.     

Al@GAP复合粒子对LLM-105热分解性能的影响

为防止铝粉在存储中氧化失活,同时为含铝炸药配方设计提供借鉴,采用聚叠氮缩水甘油醚(GAP)对不同尺寸Al粉(平均粒径分别为50nm和1~2μm)进行包覆改性,获得Al@GAP复合粒子;采用扫描电镜(SEM)、透射电镜(TEM)表征其形貌;用差示扫描量热法(DSC)对不同质量比的(Al@GAP)/LLM-105混合体系的热分解过程进行了研究。结果表明,采用两步包覆法获得了不同尺寸Al粉表面包覆GAP的核壳结构复合粒子;相较于包覆前的微米级Al粉,加入GAP包覆的纳米Al粉后混合体系的热分解峰温明显降低;当Al粉质量分数大于10%时,GAP包覆后的(Al@GAP)/LLM-105混合体系的熵变(ΔS~≠)和焓变(ΔH~≠)较Al/LLM-105混合体系有所减小;(Al@GAP)/LLM-105混合体系的活化能、热爆炸临界温度及热力学参数ΔS~≠和ΔH~≠随纳米Al粉含量的增加而降低,当Al粉质量分数为30%时,较LLM-105分别降低4kJ/mol、3℃、4.3J/(mol·K)、4.2kJ/mol。     

Effects of Aluminum Particle Size on the Detonation Pressure of TNT/Al

To better understand the influence of the aluminum particle size on the detonation pressure of TNT/Al, electrical conductivity experiment and detonation pressure experiment were performed in this study. Four types of TNT/Al were considered, in which the particle size of aluminum was 50 nm, 100 nm, 1.50 μm, and 9.79 μm, respectively. The combustion process of Al in TNT/Al was detected by electrical conductivity experiment, and the detonation pressures of TNT/Al were measured by using the manganin pressure sensors. According to the experimental results, the Chapman Jouguet (CJ) pressure of the explosive containing nano‐sized aluminum is higher than the explosive containing micron‐sized aluminum powder because of the combustion of nano‐sized aluminum in the detonation reaction zone. In addition, a smaller aluminum particle size in TNT/Al is associated with a slower detonation pressure attenuation. This study gives a clearer picture of how aluminum particle size contributes to detonation pressure on timescales from 0 to 0.82 μs.     

纳米铝粉对硝胺炸药热分解催化性能的影响

采用直流电弧等离子体蒸发法制备了高纯度的纳米铝粉,并用比表面积分析仪和扫描电子显微镜(SEM)对样品进行了表征.将纳米铝粉与硝胺炸药HMX和RDX用研磨混合法制成混合粒子,用DSC对单质HMX和RDX炸药以及纳米铝粉/硝胺炸药混合物进行催化特性测试,并对样品的热分解动力学和热力学参数进行了计算和对比.结果表明,加入纳米铝粉后,HMX和RDX在不同升温速率(2、5、10、20 K/min)下的放热峰峰温降低,活化能分别降低15和16 kJ/mol,热力学参数都有明显变化.纳米铝粉对HMX和RDX有明显的热分解催化作用.     

TATB的热分解及其在[Emim]Ac/DMSO溶剂中的热爆炸特性

用DSC-TG研究了TATB的热分解过程。根据升温速率分别为5、10、15、20K/min的DSC和TG-DTG曲线计算了分解反应的活化能(E)、指前因子(A)和120℃时的速率常数(k120),并计算了升温速率为5K/min时,TATB分解峰值温度时的分解反应活化焓、活化熵和活化自由能,用小容量测试法研究了TATB在1-乙基-3-甲基咪唑醋酸盐/二甲基亚砜([Emim]Ac/DMSO)溶剂中的热爆炸特性。结果表明,采用Kissinger法和Ozawa法计算得到TATB分解反应的活化能分别为212.1和212.0kJ/mol,采用Rogers公式和Arrhenius公式计算得到A和k120值分别为5.87×1016s-1和3.87×10-12s-1;升温速率为5K/min条件下,TATB分解峰值温度时的分解反应活化焓、活化熵和活化自由能分别为206kJ/mol、61.42J/(K·mol)和167.39kJ/mol,TATB粉末的临界爆炸温度为336.6℃;TATB在[Emim]Ac/DMSO溶剂中不爆炸。     

Al2O歧化法制备微细Al2O3/Al复合粉体

真空条件下,以Al2O3和Al为原料,通过Al2O歧化法制备微细Al2O3/Al复合粉体.XRD和SEM分析表明:在反应温度为1200～1400℃时,随着温度的升高,粉体中氧化铝含量升高;冷凝温度约为550～750℃时,复合粉体中的氧化铝包括稳定晶型和不稳定晶型;冷凝温度约为1100～1300℃时,复合粉体中的氧化铝全部为稳定晶型;冷凝温度约为550～650℃时,复合粉体的平均粒径小于0.5μm;冷凝温度约为750℃时,铝熔化、微粒团聚;冷凝温度约为1100～1200℃时,铝形成铝珠,氧化铝为不规则状、平均粒径小于2μm;冷凝温度约为1300℃时,氧化铝为片状.因此,通过选取合适的反应温度、冷凝温度,可以控制Al2O3/Al复合粉体中氧化铝的含量、晶型和粒径.     

RDX热分解的TG-DSC-QMS-FTIR同步动力学

采用TG-DSC-QMS-FTIR同步动力学技术对RDX的热分解过程进行了研究,结果表明,RDX在熔融之后发生分解,可以确定RDX的产物有C、H2O、CH2O、N2O、CO、CO2、NO2,可能有CH4和NH3,而几乎没有NO.采用多元非线性拟合技术进行动力学参数计算,结果表明,RDX的分解过程大致可以分为3个连续步骤,第1步反应的活化能为235 kJ/mol,指前因子log(A/s-1)为22,反应级数为0.6,主要气体产物为CO2、NO2和CH2O;第2步反应的活化能为110 kJ/mol,指前因子log(A/s-1)为1.5,反应级数为1.7,主要的气体产物是N2O、H2O、CH4、NH3、C2O+/C3H+4、CN+/C2H+3、CHO+/C2H+;第3步反应的活化能为223 kJ/mol,指前因子log(A/s-1)为20.9,反应级数为4,主要的产物是C和CO.     

RDX/AP/Al/SiO2亚微米复合含能材料的制备与表征

将高能氧化剂（AP）和正硅酸乙酯（TEOS）共溶,纳米Al粉均匀地分散在共溶剂中,控制反应条件,使体系逐渐生成SiO2溶胶,在凝胶点加入RDX的DMF溶液并凝胶化,制得RDX/AP/Al/SiO2凝胶复合物。扫描电镜分析表明,各组分在亚微米尺度均匀复合,构成粒度在0.2μm-2.0μm的复合粒子,形貌近球形且较为均匀。与相同条件机械掺杂的RDX、NH4ClO4、Al、SiO2相比,其撞击感度明显降低。     

Crosslinking of epoxy-modified phenol novolac (EPN) powder coatings: Particle size and adhesion

These studies were undertaken to examine how particle size of epoxy phenol novolac (EPN) powder coatings may affect adhesion to metal substrates. Particle sizes of 21 and 83 μm diameter were utilized. DSC analysis shows that the activation energies of crosslinking for the 21 μm particle size is 41 kJ/mol and 58 kJ/mol for 83 μm particle size which is attributed to the effect of particle size, and time-temperature-particle size (TTPS) parameters are used to describe powder-liquid-solid film transformation process. Although, the TTSP term represents a combination of intrinsic and extrinsic properties. We believe that this is the TTPS term that adequately describes the processes in which, in order for crosslinking reactions to occur, particles must initiate the flow. Quantitative attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopic analysis was used to follow crosslinking processes by monitoring the decrease of oxirane concentration, and showed that for thermal cure at 185°C for 20 min, the oxirane concentration decreases at a similar rate for 21 μm and 83 μm particle sizes. The results of pull-off adhesion measurements from an Al substrate show that when the 21 μm particle size is crosslinked for 10 min at 110, 140, and 170°C, adhesion is consistently higher than for the same coating system at 83 μm particle size. This difference is attributed to the finite time required for powder particles to reach a proper melt viscosity, followed by reactions of functional groups leading to crosslinking. Extended cure times to 120 min for the 83 μm particle resulted in adhesion similar to the 21 μm particle size. Studies conducted at North Dakota State University