NTO包覆HMX的钝感研究

为降低HMX的机械感度并维持其爆炸性能,采用溶液重结晶法用较钝感的3-硝基-1,2,4-三唑-5-酮(NTO)包覆HMX,并测试了其机械感度和爆速。通过SEM观察了包覆HMX的粒径、形貌及包覆钝感的工艺条件。结果表明,包覆HMX的表面形态主要受水与N-甲基吡咯烷酮(NMP)体积比、搅拌速率和冷却速率的影响。当水和NMP体积比为5、搅拌速率为300r/min、冷却速率为6K/min时,包覆HMX的表面形态最好;以水和NMP为溶剂,包覆HMX的H50值提高了14.8cm,撞击感度降低了66%,且摩擦感度从100%降低至50%。包覆HMX的爆速降低了2.8%,基本可以维持爆炸性能不变。     

表面活性剂对HMX基PBX性能的影响

采用溶液-水悬浮法,以F2602为黏结剂,Span-80、Tween-80、PVA、糊精为表面活性剂,制备了HMX基PBX;采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、差式扫描量热仪(DSC)对其进行了表征和热分析,并测试了其撞击感度。结果表明,加入表面活性剂包覆后未改变HMX的晶体结构;以Span-80为表面活性剂时包覆得到的HMX基PBX表面最光滑,包覆密实且无明显外漏现象;加入表面活性剂Span-80、Tween-80、PVA、糊精后得到的HMX基PBX的表观活化能分别为438.05、217.74、406.64、356.14kJ/mol,与未加表面活性剂的样品相比降低了35.52、255.83、66.93、117.43kJ/mol;加入Span-80的HMX基PBX热爆炸临界温度约上升1℃,表明对PBX的安定性无明显影响,撞击感度特性落高(H50)由44.9cm增加到63.2cm,提高了40.76%。     

不同粒度HMX的重结晶制备和机械感度研究

采用微团化动态结晶方法和溶剂/非溶剂滴加重结晶方法制备出中位径d50分别为0.472、6.266、36.75μm的HMX颗粒,并采用粒度分析仪和扫描电子显微镜（SEM）对3种试样的粒度进行了表征。测定了3种试样的撞击感度（特性落高H50）和摩擦感度（爆炸百分数）值。测试结果表明,撞击感度随粒度减小逐渐降低,并且在粒度降至亚微米级时降到最低;摩擦感度随粒度减小先升高再降低,而且粒度在10μm～50μm时最为钝感。     

不同胶粘剂对RDX降感效果的对比研究

为降低RDX(黑索金)炸药的机械感度,分别采用5种惰性胶粘剂[如F2602(氟橡胶)、F2604(氟橡胶)、EPDM3720(三元乙丙橡胶)、PVAc(聚醋酸乙烯酯)和Estane5703(热塑性聚氨酯)等]作为包覆剂,对RDX表面进行包覆处理。研究结果表明:不同胶粘剂均可成功包覆在RDX颗粒表面;包覆RDX的撞击感度随胶粘剂比例增加呈先升后降态势;F2602和F2604包覆RDX的摩擦感度随胶粘剂比例增加而增大,而其他3种胶粘剂的摩擦感度则随之下降。     

TEX对HMX的包覆降感

为降低HMX的机械感度并保持其爆轰性能,采用溶液-水悬浮包覆法,利用4,10-二硝基-2,6,8,12-四氧杂-4,10-二氮杂四环[5.5.0.0~(5,9).0~(3,11)]十二烷(TEX)和氟橡胶F_(2603)对HMX进行包覆降感;考察了TEX与HMX的粒度级配、主炸药质量比以及黏结剂用量对包覆炸药感度的影响;观察了TEX/HMX包覆炸药的微观形貌,测试其晶型结构、撞击感度、摩擦感度和爆速等参数,并进行了对比分析。结果表明,TEX可在HMX的表面形成保护层;黏结剂F_(2603)质量分数3%时为最佳用量,且包覆后HMX的晶型保持不变,仍为β型;超细TEX(d_(50)=4.532μm)和HMX(d_(50)=10.234μm)粒度级配下的降感效果最好,与原料HMX相比,TEX/HMX(质量分数30%TEX)混合炸药的撞击感度和摩擦感度分别降低了48%和68%,在装药密度为1.72g/cm~3时的实测爆速可达到7 932m/s。     

PTFE/Al/Fe_2O_3复合材料的性能

研究了以聚四氟乙烯(PTFE)为基体,Al/Fe_2O_3混合物为填料的复合材料的准静态压缩性能和撞击感度,探讨了不同烧结温度和不同PTFE含量对复合材料性能的影响。结果表明,随着PTFE含量以及烧结温度的增加,材料强度均呈现先增加后降低的趋势。PTFE质量分数在70%和80%的PTFE/Al/Fe_2O_3复合材料在烧结温度340~370℃的范围时,能够在准静态压缩过程中产生剧烈反应,发出爆炸声和明亮的火光。370℃烧结的PTFE质量分数为70%的复合材料的撞击感度最高,特性落高值仅有37 cm,非常敏感。在同一烧结温度下,随着PTFE含量的增加,复合材料的撞击感度先增加后降低;PTFE含量相同时,随烧结温度的增加,材料撞击感度为先增加后降低。     

水悬浮法制备-εHNIW基传爆药的工艺研究

为获得高能低感传爆药,以六硝基六氮杂异伍兹烷为主体炸药,用水悬浮法制备了ε-HNIW为基的传爆药.通过正交试验优化了制备工艺,并对影响包覆效果的主要因素进行了研究.用傅立叶红外光谱(FT-IR)、扫描电子显微镜(SEM)及撞击感度测试等手段对包覆样品进行表征.结果表明,影响包覆效果的因素顺序为:温度＞搅拌速度＞加料速度＞真空度;确定了最佳工艺条件:试验温度70℃、真空度0.05 MPa、搅拌速度700 r/min、加料速度0.725 mL/s.包覆过程中ε-HNIW晶型结构没有发生改变;包覆后样品撞击感度的特性落高H50比原料ε-HNIW提高了27 cm.     

TATB/HMX共晶炸药的制备及性能研究

采用溶剂/非溶剂法,在超声辅助的情况下,制备了TATB/HMX共晶炸药;探究了TATB/HMX共晶技术的影响因素;计算了TATB/HMX共晶炸药的理论密度和理论爆速;采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)和差示扫描热量法(DSC)对其进行表征和热分析,并测试了其撞击感度。结果表明,制备TATB/HMX共晶的最佳工艺条件为:以[Emim]Ac/DMSO为复合溶剂,TATB和HMX投料比(摩尔比)为3∶7,温度为80℃,搅拌速率为500r/min;与原料相比,TATB/HMX共晶分子在结构上发生改变;TATB/HMX共晶炸药颗粒大小约为2μm,形貌为六边形晶体;共晶炸药的热安定性优于原料HMX,其特性落高比原料HMX高74cm,撞击感度明显降低;理论密度为1.891g/cm~3,理论爆速为8.758km/s,表明其爆炸性能良好。     

Pickering乳液聚合法制备TATB/HMX基复合微球

为了提升HMX的安全及应用性能,采用Pickering乳液聚合法,以固体粒子氧化石墨烯(GO)为稳定剂,分别以聚醋酸乙烯酯(PVAc)和聚苯乙烯(PSt)为黏结剂制备了两种TATB/HMX基复合粒子;通过扫描电子显微镜(SEM)、X射线衍射仪(XRD)、差示扫描量热仪(DSC)和X射线光电子能谱仪(XPS)对样品进行了表征,并测试了其撞击感度和摩擦感度。结果表明,制备的TATB/HMX基复合粒子均为表面均匀密实的球形颗粒,所含HMX和TATB的炸药晶型均未改变;与HMX原料相比,复合粒子的表观活化能(E_a)提高,其中TATB/HMX/PVAc/GO复合粒子的E_a提高了44.18kJ/mol, TATB/HMX/PSt/GO的E_a提高了40.5kJ/mol;撞击感度和摩擦感度明显降低,以PVAc为黏结剂更适合复合粒子的制备,其临界撞击能量由5.5J提升至60J,临界摩擦压力由128N提升至324N,说明制备的复合微球的热安全性和机械安全性大大提高。     

微流控法制备超细HMX/FOX-7复合物及其性能测试

为了降低HMX感度,提高使用安全性,选用低感度含能材料FOX-7为包覆剂,利用微流控技术制备得到超细HMX/FOX-7复合物。采用红外、XRD分析表征了其结构,采用SEM分析了复合物的微观形貌,并对其进行热性能、感度性能及点火燃烧性能测试研究。结果表明,基于微流控技术制备的超细HMX/FOX-7复合物粒径范围0.92～2.91μm,平均粒径1.37μm,球形度较好,粒径分布窄;相比于传统宏观尺度搅拌法,微尺度制备条件使得HMX降感效果增强,获得的复合物具有更高的热稳定性和更优良的感度性能,热分解温度较传统法推迟11.8℃,撞击感度和摩擦感度分别由56%和52%降至32%和28%;HMX/FOX-7复合物的点火延迟时间随着激光功率密度的增加呈现递减的趋势,在相同功率密度条件下随着FOX-7含量的增加,复合物最小点火能量增大,点火延迟时间增加;与原料HMX相比,复合物的点火燃烧火焰更为明亮,火焰传播速率更快。     

Encapsulation of Cyclotetramethylenetetranitramine (HMX) by Electrostatically Self‐Assembled Graphene Oxide for Desensitization

To improve the safety of cyclotetramethylenetetranitramine (HMX) particles, a novel strategy was developed for the fabrication of graphene oxide encapsulated HMX (HMX@GO) by electrostatic self‐assembly between graphene oxide and HMX particles. The prepared samples were characterized by optical microscopy, scanning electron microscopy, Raman spectroscopy, X‐ray photon spectroscopy, thermogravimetry, differential scanning calorimetry and water contact angle tests. The results revealed that GO sheets were coated densely and homogeneously on the HMX particles in a HMX@GO composite at a low GO content of about 0.23 wt %. Compared with that of raw HMX, the impact sensitivity of the HMX@GO composite decreased from 100 % to 30 %, and the 50 % probability of required ignition energy (E₅₀) in the electrostatic spark sensitivity test increased from 0.66 J for HMX to 1.12 J for the HMX@GO composite, suggesting that the electrostatically self‐assembled GO coating layer could obviously enhance the safety of HMX.     

超临界流体反溶剂法制备超细HMX传爆药

为了克服超细炸药在常规包覆过程中易团聚的缺点,采用超临界流体反溶剂法( SAS)制备了以亚微米HMX为主体炸药的超细传爆药,探讨了工艺条件对亚微米HMX包覆效果的影响.结果表明,影响亚微米HMX包覆效果的主要因素有初始浓度、系统温度、系统压力、平均压力升高速率和平均压力下降速率.在加入20 mL的乙酸乙酯、系统压力9....     

Effect of Sandpaper and Grain Size on Non‐Shock Initiated Reactions in HMX

Three grades of HMX samples, coarse (A), coarse with a small amount of fines (B), and ultra‐fine (F), were tested for impact sensitivity by ERL drop hammer. The Type 12A test used sandpapers of three different compositions, 120‐, 180‐grit Si/C and 180‐grit garnet. Reaction was accounted for by operator observation and microphone. The results showed different sensitivity for each of the HMX types. The F‐HMX was the smallest in average particle size and was the least sensitive to impact. The A‐HMX was the next most stable and the B‐HMX was the most sensitive to impact. The spent samples from the drop hammer testing of B‐HMX and F‐HMX were further evaluated with optical imaging. Conditions were selected that were near the DH₅₀ values of the specific HMX. Previous literature has cited localized hot spot formation to be the probable cause of non‐shock initiated reactions leading to impact sensitivity. This study yielded a plethora of samples exhibiting hot spots for HMX materials, both without and with proximity to grit particles. Hot spots in the proximity of grit particles gave the most dramatic hot spots, but both types of hot spots were exhibited in samples considered reacted and non‐reacted. The F‐HMX, even though the most stable to impact sensitivity, exhibited the most and best resolved hot spots of all the samples and conditions. Foreign objects were also observed in some of the samples. Previous work has shown metal particles coming from wear of the anvils used in the drop hammer experiment can also form hot spots. However, none of the samples here with metal particles exhibited, in proximity, hot spot formation.     

HMX/SiO2凝胶的制备及表征

基于溶胶-凝胶工艺,在二氧化硅(SiO2)溶胶向凝胶的相变作用过程,在凝胶点时加入HMX的二甲亚砜(DMSO)溶液,制备出HMX/SiO2(质量比80∶20)凝胶。用扫描电镜和傅里叶变换红外光谱对产物进行表征。结果表明,HMX/SiO2凝胶呈近似直径为0.5～1.0μm球形。与相同质量分数的HMX/SiO2机械掺杂混合物相比,HMX/SiO2凝胶的特性落高H50由31.70cm提高至52.24cm,摩擦感度由30%降至0。在铜管约束条件下,当平均装药的密度为1.15g/cm3时,临界传爆直径约为0.6mm。     

Replacement of virgin rubbers by waste ground vulcanizates in blends of silicone rubber and fluororubber based on tetrafluoroethylene/propylene/vinylidene fluoride terpolymer

This study reports the results of investigations on blends of silicone rubber and fluororubber based on tetrafluoroethylene/propylene/vinylidene fluoride terpolymer and the effects of replacement of silicone rubber and/or fluororubber in their 50/50 blend by the respective vulcanizate powders of known compositions. To simulate the aging condition of factory wastes, the silicone rubber or fluororubber vulcanizates were aged for 72 h at 200°C and then converted into powder by mechanical grinding. The fluororubber vulcanizate powder (FVP), mostly spherical in shape with average diameter varying between 2 and 10 μm, exists in a highly aggregated state displaying chainlike structures that, however, break down during blending with virgin rubbers. The silicone rubber vulcanizate powder (SVP) is irregular in shape, with larger particles in the range of 30–100 μm, and the smaller particles exist in highly aggregated chainlike structures, as in the case of FVP, which break down during milling to mostly spherical particles of 2–10 μm in diameter. Measurements of physical properties reveal that the blends of silicone rubber and fluororubber are technologically compatible. SEM photomicrographs of THF‐etched samples show the biphasic structure of the blends, in which the fluororubber forms the dispersed phase in a continuous silicone rubber matrix of lower viscosity. Replacement of silicone rubber in the 50/50 silicone rubber/fluororubber blend by its vulcanizate powder (SVP) increases the Mooney viscosity, but replacement of fluororubber in the blend by its vulcanizate powder (FVP) has little effect on the Mooney viscosity. Monsanto rheometric studies reveal that replacement of silicone rubber by SVP or fluororubber by FVP in the 50/50 silicone rubber/fluororubber blend increases the minimum rheometric torque but decreases the maximum torque, and the effect is more pronounced in the case of SVP. Furthermore, the replacement of silicone rubber in the blend by SVP causes a decline in the physical properties (25% replacement causing about 10% decline in properties, for example), whereas even 75% replacement of fluororubber by FVP has little effect on the physical properties. When both silicone rubber and fluororubber are partially replaced by SVP and FVP in the same blend, properties of the resulting blend composition are controlled more by SVP incorporation, whereas fluororubber replacement has only a marginal effect on blend properties. It is evident from dynamic mechanical spectra that the blends are immiscible in all compositions and addition of SVP or FVP does not affect the glass–rubber transitions of the constituent polymers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2326–2341, 2001     

Preparation and Characterization of Reticular Nano‐HMX

Reticularly structured HMX (octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine) of nano‐size particles was simply prepared by reprecipitation at room temperature. The sample prepared by reprecipitation was characterized by SEM, TEM, XRD, DSC, and drop weight impact. The results of SEM and TEM indicated that spherical HMX particles of about 50 nm in diameter aggregated into reticularly structured conglomerates. There are two phases (γ‐ and β‐HMX) existing in the reticularly structured HMX as shown in the XRD pattern. It was also proved by DSC that the maximum energy release during decomposition of the reticularly structured HMX is at lower temperature. In addition, the testing result of drop weight impact showed that the reticularly structured HMX is less sensitive to impact.     

配方因素对氟橡胶高温撕裂性能的影响

研究了硫化剂品种、双酚AF用量、促进剂BPP用量、补强剂品种及炭黑N990用量对不同测试温度下氟橡胶撕裂强度的影响,采用核磁共振法测定了不同温度下氟橡胶硫化胶的交联密度,研究了氟橡胶的高温撕裂强度与其交联密度间的关系。结果表明,随着测试温度的增加(25℃增加到200℃),不同配方的氟橡胶的撕裂强度均明显降低。在100~200℃温度范围内,双酚AF/BPP硫化的氟橡胶的撕裂强度高于过氧化物或胺类硫化氟橡胶的撕裂强度。随着双酚AF用量的增大,氟橡胶的常温撕裂强度明显降低,而高温撕裂强度略有下降。促进剂BPP用量增大,氟橡胶的常温和高温撕裂强度均变化不大。几种补强剂中,沉淀法白炭黑补强氟橡胶在200℃时的撕裂强度仅为25℃时撕裂强度的0.6%。测试温度从25℃升至200℃,炭黑N990补强氟橡胶的撕裂强度降低幅度较小,随着N990用量的增大,氟橡胶的常温撕裂强度增幅明显,而高温撕裂强度略有提高。测试温度升高,氟橡胶硫化胶的交联密度减小,同时撕裂强度也降低,双酚硫化时,在相同测试温度下,氟橡胶的交联密度越小,撕裂强度越大。     

DNP/HMX熔铸炸药的流变性能

为了解3,4-二硝基吡唑(DNP)/HMX悬浮液在不同影响因素下的流变行为,采用Brookfield R/S Plus流变仪对其流变性能进行测试,分析了HMX含量、粒度、颗粒级配、体系温度以及不同添加剂对悬浮液流变性能的影响。结果表明,DNP单质为牛顿流体,表观黏度约为16.4mPa·s,比TNT高82%,比DNAN高140%;同一剪切速率下,DNP/HMX悬浮液表观黏度随固含量的增加而增加,当HMX质量分数为30%时,悬浮液近似牛顿流体;HMX质量分数高于30%时,表观黏度随剪切速率的增加呈指数型下降的趋势愈发明显;悬浮液表观黏度随颗粒粒径的增大和温度的增加而降低,当温度从95℃升到105℃时,黏流活化能(E)从29211J/mol增至38458J/mol;固含量为60%时,平均粒径(d50)分别为16.6μm和575.6μm的HMX颗粒的最佳质量比为1∶5,此时悬浮液表观黏度最小。N-甲基-4-硝基苯胺(MNA)降低了悬浮液的表观黏度,乙酸丁酸纤维素(CAB)和微晶蜡-80(MV80)增加了悬浮液的表观黏度。