含废弃丁羟推进剂的凝胶炸药

为安全处理和再利用废弃固体推进剂,通过添加单基药将丁羟推进剂再利用制备了灌注式凝胶炸药.采用验证板试验及电离探针法研究了不同装药配比、推进剂颗粒尺寸及装药直径对炸药爆轰性能的影响.结果表明,丁羟推进剂难以发生爆轰,若添加适量单基药,能显著提高炸药的爆轰感度,并降低其临界直径;该凝胶炸药密度为1.6 g/cm3,直径为7...     

HTPB推进剂危险性实验研究

依据联合国危险品分级方法,探讨了热刺激、机械刺激和冲击波刺激对低燃速HTPB推进剂、高燃速HTPB推进剂和四组元HTPB推进剂危险性的影响。结果表明,3种HTPB推进剂的热安定性良好,但对火焰热刺激均十分敏感,具有爆燃性;高燃速HTPB推进剂对机械刺激也极其敏感,摩擦感度(p)为96%,撞击感度特性(H50)为37.2 cm。在无约束条件下,3种HTPB推进剂裸药柱对雷管爆轰作用不敏感,而在钢管的强约束条件下,四组元HTPB推进剂对爆轰冲击波作用敏感,隔板值大于18mm。     

适应高压强的HTPB推进剂的燃烧性能

为改善高压强下HTPB推进剂的燃烧特性,研究了碳酸盐复合调节剂、二茂铁衍生物G、高氮化合物M、纳米铝粉和纳米金属氧化物对HTPB推进剂燃烧性能的影响.结果表明,碳酸盐复合调节剂能够降低推进剂的燃速和压强指数;二茂铁衍生物G能够提高推进剂的燃速,同时将推进剂在8.60～17.12MPa下的压强指数降至0.27;高氮化合物也可降低推进剂的燃速和压强指数;将高氮化合物M与二茂铁衍生物G配合使用可将推进剂在8.63～16.48MPa下的压强指数降至0.24; 纳米铝粉和包覆的纳米金属氧化物可明显降低推进剂的燃速压强指数.     

快燃物ACP在丁羟复合固体推进剂中的应用

采用药条燃速仪试验和Ф64mm发动机点火试验,研究了不同含量的快燃物ACP对低、中、高燃速丁羟复合固体推进剂燃烧性能的影响。结果表明,快燃物ACP能明显提高推进剂的燃速,使6．86～15MPa下推进剂的燃速压强指数有明显增大的趋势,在低、中、高燃速推进剂配方中加入质量分数为5％的ACP,15MPa下的燃速分别提高11．3％,82．9％,67．8％。Ф64mm发动机试验表明,含ACP的推进剂在发动机中能够稳定燃烧,发动机p-t工作曲线稳定。获得了ACP使推进剂产生非平行层燃烧从而大幅度提高燃速的初步证据。     

醇胺类键合剂在丁羟推进剂中的应用进展

介绍醇胺类键合剂的发展现状,分析键合剂在复合推进剂中的键合机理及其在丁羟推进剂中的应用,总结了醇胺类键合剂在应用中所存在的问题及发展趋势。认为醇胺类键合剂可明显改善丁羟推进剂的性能。     

黏合剂对NEPE推进剂力学性能的影响研究进展

综述了黏合剂中多元醇的种类、相对分子质量、官能度等和异氰酸酯的种类、异氰酸酯指数以及不同的扩链剂、交联剂、增塑剂及其用量等因素对NEPE推进剂力学性能的影响。     

HTPB推进剂贮存老化对其反复拉伸破坏能的影响

由单轴反复拉伸试验分别研究了含键合型防老添加剂和防老剂 H的 HTPB推进剂破坏能与贮存老化时间的关系。结果表明 ,键合型防老添加剂能增强氧化剂与粘结剂基体间的界面粘接能力 ,使其推进剂的破坏能低于含防老剂 H的推进剂     

Burning Mechanism of Aluminized Solid Rocket Propellants Based on Energetic Binders

This paper reports results obtained from an experimental study of the combustion mechanism of aluminized propellants based on an energetic binder. The techniques used in this investigation include:     

Effect of Binders on the Burning Rate of AP Composite Propellants

The burning rate characteristics of ammonium perchlorate (AP) based composite propellants is studied as a function of the chemical nature of the polymers used as binders. The following five types of polymers are used:(1) hydroxy‐terminated polybutadiene (HTPB)(2) polypropyleneglycol (PPG)(3) polysulfide (PS)(4) polyesterpolyol (PO)(5) azidomethylmethyloxetane (AMMO) Experiments are conducted using differential thermal analysis (DTA), thermogravimetric analysis (TG), and burning rate analysis. The AP/PS propellant shows the highest burning rate and the AP/PO propellant shows the lowest burning rate within the propellants tested. Though the burning rate appears to be very dependent on the type of binder used, the characteristics of burning rate versus pressure cannot be correlated with the thermochemical data obtained by DTA and TG. The results of the photographic observation of the burning surface indicate that the formation of a melting layer of the binder reduces the burning rate due to the reduced reaction rate between the binder and the AP particles.     

Estimation of Aluminium in HTPB Based Composite Solid Propellants by hydrogen evolution method

Hydrogen gas evolution method has been applied to determine the percentage of aluminium (Al) in hydroxy-terminated polybutadiene (HTPB) based composite solid propellants premix/pastes. The determination is not effected by the presence of Zn, Fe, Cu or small amounts of silicon but magnesium has been found to interfere in the analysis. The results are obtained with remarkable accuracy and reproducibility.     

HTPB/AP/Al复合推进剂燃速降速剂研究

通过测定5．1MPa压强下HTPB／AP／Al复合推进剂药条静态燃速和BSF075mm、BSF0165mm标准发动机实验,研究了（NH4）2C2O4,LiF,CaCO3,SrCO3及季铵盐等燃速调节剂对推进剂燃烧性能、能量性能等的影响。结果表明,季铵盐降速效率最高,季铵盐与碳酸盐组合使用可使固体质量分数为87％的推进剂在5．1MPa压强下的静态燃速降至3mm／s左右。BSFΦ75mm发动机测试表明,含季铵盐与碳酸盐组合降速剂的推进剂配方在3．45～12．17MPa压强范围内的压强指数为0．2,达到了平台推进剂水平,密度比冲较相近燃速的含草酸铵推进剂高2．8％,且内弹道曲线更稳定。     

水射流出口压力对HTPB推进剂冲击安全性的影响

基于临界起爆判据Pnτ=K,通过对高压水射流出口压力的合理选择,研究HTPB推进剂发生冲蚀破碎过程中的安全性。依据水射流的冲击理论和推进剂的力学特性,得出最低出口压力,并讨论其对推进剂冲击安全性的影响。建立以水锤压力为危险源的飞片冲击模型,以临界起爆压力衡量水锤压力在SDT过程中的安全性。结果表明,在任何出口压力下,水锤压力对于SDT过程中的安全性无影响;而当出口压力达到100MPa时,在滞止压力作用下的温升变化异常,推进剂内部温度已接近临界温度,具有较大的危险性。通过评判两个阶段对HTPB推进剂的冲击安全性,确定出口压力的安全区间为60～100MPa。     

Mechanical Properties of Composite AP/HTPB Propellants Containing Novel Titania Nanoparticles

Modern chemical synthesis techniques have allowed for improved incorporation of nano‐scale additives into solid propellants. Various methods were implemented to incorporate titania nanoparticles into three representative ammonium perchlorate composite propellants (APCP), and the mechanical properties of each formulation were tested and compared to those of an analogous baseline. Advanced imaging techniques were applied to all particle synthesis methods to characterize particle size and particle network type and size. Uniaxial tensile testing was performed to measure propellant ultimate strength, ductility, and elastic modulus. In general, the addition of nano‐titania additives to the propellant decreased propellant strength and modulus, but improved ductility. Propellant formulations containing in‐situ titania exhibited an increase in ductility of 11 %, 286 %, and 186 % with a corresponding reduction in strength of 82 %, 52 %, and 17 % over analogous baselines. These trends corresponded to a simultaneous decrease in propellant density, indicating that when implementing nano‐sized additives, care must be taken to monitor the effect of the altered manufacturing techniques on propellant physical properties in addition to just monitoring burning rates. Tailoring of propellant manufacturing procedures and the addition of Tepanol bonding agent to an in‐situ APCP formulation fully recovered the propellant density and ultimate strength while retaining the enhanced ductility.     

Iron Nanoparticle Additives as Burning Rate Enhancers in AP/HTPB Composite Propellants

Burning rate measurements were carried out for ammonium perchlorate/hydroxyl‐terminated polybutadiene (AP/HTPB) composite propellants with iron (Fe) nanoparticles as additives. Experiments were performed in a strand burner at pressures from 0.2 to 10 MPa for propellants containing approximately 80 % AP and Fe nanoparticles (60–80 nm) at concentration from 0 to 3 % by weight. It was found that the addition of 1 % Fe nanoparticles increased burning rate by factors of 1.2–1.6. Because Fe nanoparticles are oxidized on the surface and have high surface‐to‐volume ratio, they provide a large surface area of Fe₂O₃ for AP thermal decomposition catalysis at the burning propellant surface, while also providing added energy release due to the oxidation of nanoparticle sub‐shell Fe. The increase in burning rate due to Fe nanoparticle content is similar to the increase in burning rate caused by the addition of iron oxide (Fe₂O₃) particles observed in prior literature.     

Synthesis and Interfacial Adhesion Interaction of Borate Ester Bonding Agents Used for HTPB Propellants

The external monomers N‐methyl‐N,N‐diethanolamine, N‐butyl‐N,N‐diethanolamine, N‐(2‐cyanoethyl) diethanolamine, and N,N‐dihydroxyl‐3‐aminmethyl propionate were synthesized by modification of diethanolamine to evaluate the effects of external monomer molecular structure on the interfacial interactions of borate ester bonding agent (BEBA) applied in four‐component hydroxy‐terminated polybutadiene (HTPB) propellants. The compounds were characterized by IR and NMR spectroscopy. A series of BEBAs were synthesized using the as‐synthesized external monomers as well as diethanolamine. The interfacial interactions are evaluated using thermodynamic methods including acid‐base interaction enthalpy and wetting theory among the components in HTPB propellants. The experimental results indicate that the addition of BEBA‐3 prepared from N‐(2‐cyanoethyl) diethanolamine can significantly improve the interaction ethalpies and surface properties of the components in HTPB propellants. The results from the mechanical properties testing and SEM observations are in accordance with the results from the thermodynamic analysis of the interfacial adhesion interactions.     

Preliminary Characterization of Propellants Based on p(GA/BAMO) and pAMMO Binders

In previous papers, the synthesis and characterization of OH‐terminated glycidyl azide‐r‐(3,3‐bis(azidomethyl)oxetane) copolymers (GA/BAMO) and poly‐3‐azidomethyl‐3‐methyl oxetane (pAMMO) by azidation of their respective polymeric substrates were described. The main objective was the preparation of amorphous azido‐polymers, as substitutes of hydroxy‐terminated polybutadiene (HTPB) in new formulations of energetic propellants. Here, the subsequent characterization of both the binders is presented. First of all, several isocyanates were checked in order to optimize the curing reaction, and then two small‐scale formulations of a propellant, based on aluminium and ammonium perchlorate, were prepared and characterized. Finally, the mechanical properties and burning rate were compared to those of a similar propellant based on HTPB as binder.     

Development of MTV Compositions as Igniter for HTPB/AP Based Composite Propellants

MTV compositions were prepared by keeping the magnesium/Teflon ratio constant and increasing the Viton content of the mixture up to 14% by an increment of 2% to investigate the effect of binder content on the heat of explosion, which is found to increase with the increasing Viton percentage as the magnesium content concomitantly goes down toward the stoichiometric value. In the second part of the study, fuel-rich MTV compositions were prepared by changing the magnesium content and keeping the Viton fraction constant at a specific value to investigate the effect of magnesium content on the heat of explosion and combustion characteristics. The observed general trend is that the heat of explosion of MTV compositions decreases as the magnesium content increases. All the MTV compositions were tested in a closed vessel to measure the maximum pressure achieved and the rate of reaching this pressure. The ignition performance of three selected MTV compositions was examined in 2.75 inch rocket motor by using the same charge of igniter and the same HTPB/AP composite propellant of the equal amount in each test. Two of them have excellent ignition performance and, therefore, can be used as igniter for the HTPB/AP based composite rocket propellants.     

Reactions in Stabilizer and Between Stabilizer and Nitrocellulose in Propellants

HPLC analysis of the stabilizer is one of the major methods in use for surveillance testing of diphenylamine (DPA) stabilized propellants. Often 0.2% DPA is used as a minimum content for safe propellants. In most cases the propellant can be stored much longer after this limit has been reached without any risk for self‐ignition. We report here about a reaction where DPA bonds to nitrocellulose, leaving a non extractable aromatic stabilizing compound left in the propellant, resulting in a longer time to autocatalysis than predicted. Diphenylnitramine is discussed as a possible intermediary compound occurring from the reaction between DPA and nitrocellulose. This should add to a better understanding of the degradation processes in propellants.     

Differential Scanning Calorimetric Study of HTPB based Composite Propellants in Presence of Nano Ferric Oxide

A comparative study of the thermal decomposition of ammonium perchlorate (AP)/hydroxy terminated polybutadiene (HTPB) based composite propellants has been carried out in presence and absence of nano iron oxide at different heating rates in a dynamic nitrogen atmosphere using differential scanning calorimetry. The pronounced effect was a lowering of the high temperature decomposition by 49 °C. A higher heat release up to 40% was observed in presence of nano ferric oxide (3.5 nm). The kinetic parameters were evaluated using the Kissinger method. The increase of the rate constant in the catalyzed propellant confirmed the enhancement of the catalytic activity of ammonium perchlorate. The scanning electron micrographs of nano Fe₂O₃ incorporated in HTPB revealed a well‐separated characteristic necklace‐like structure of α‐Fe₂O₃ particles at high magnification.     

丁羟推进剂黏结体系中增塑剂迁移的分子模拟

为克服固体推进剂中增塑剂与黏结体系之间加速老化实验手段的不足,构建了增塑剂和黏结体系的分子模型.利用分子模拟方法在COMPASS力场下分析了增塑剂癸二酸二辛酯(DOS)在由端羟基聚丁二烯(HTPB)和异佛尔酮二异氰酸酯(IPDI)组成的黏接体系中的相容性和扩散性.用无定形动力学方法计算组分的溶度参数,判断DOS与HTPB、IPDI的相容性.结果表明,DOS与HTPB、IPDI相容性较好.这与由共混方法计算的结合能得到相容性好的结论一致;通过分子动力学方法模拟计算得到增塑剂DOS在黏结体系(HTPB-IPDI)中的扩散系数为1.2×10-7cm2/s.