纳米HMX的制备及热性能分析和感度研究

采用机械球磨法批量制备了纳米奥克托今(HMX),用激光粒度仪分析其粒度分布,并用扫描电子显微镜(SEM)观察其大小和形貌;使用热重分析仪(TG)和差示扫描量热仪(DSC)分析其热分解特性和热安定性;同时对纳米HMX的5 s爆发点和感度进行了测试。结果表明,制备的HMX颗粒大部分在100 nm以下;与原料HMX相比,纳米HMX的最大热失重温度降低了3.66℃,表观活化能E a降低了11.19 kJ/mol,自发火温度降低了2.11K;5s爆发点降低了4.9℃,纳米HMX的静电感度和火焰感度与原料HMX相当,纳米HMX的摩擦感度、撞击感度和冲击波感度分别降低了32.5%、20.2%和56.4%。     

纳米RDX的热性能及感度研究磁

采用激光粒度仪跟踪粒度分布,用扫描电子显微镜（SEM）和透射电子显微镜（TEM）观察颗粒大小和形貌;通过热重（TG）和差示扫描量热法（DSC）分析了使用HLGB-10型粉碎机批量制备纳米黑索今（RDX）的热分解特性,并测定了5s爆发点和感度。研究结果表明,制备的纳米RDX粒度分布窄;与原料RDX相比,活化能和5S爆发点稍有降低,热安定性基本不变,静电感度与火焰感度与原料RDX相当;摩擦、撞击和冲击波感度分别比原料RDX降低了37．5％、92．8％和51．0％。     

降低超细高氯酸铵感度的方法研究

为了降低超细高氯酸铵(AP)的机械感度,以十八烷胺为包覆剂,经气流粉碎工艺,制备了超细AP包覆粒子。通过对超细AP包覆粒子进行粒度分析、SEM分析、DSC分析及感度检测,研究了超细AP包覆粒子的包覆效果、热分解特性及感度特性。试验结果表明:超细AP包覆粒子,粒度为D50=5.8μm,表面有包覆层存在;超细AP包覆粒子的感度,与超细AP样品相比,当包覆剂质量分数为1%时,撞击感度降低31.2%,摩擦感度降低12.0%;当包覆剂质量分数为3%时,撞击感度降低34.5%,摩擦感度降低22.0%,且包覆剂用量越大,撞击感度和摩擦感度越低;但包覆剂对AP的热分解会产生一定的负面影响,质量分数应≤1%。     

氟橡胶包覆对CL-20机械感度及爆轰特性的影响研究

为研究CL-20晶体表面钝化对安全及爆轰性能的影响,采用氟橡胶F2311作为黏结剂,基于水悬浮法对比研究了CL-20包覆前、后的机械感度及爆轰性能变化规律。实验结果表明：F2311包覆可以显著改善CL-20材料的表面缺陷;在-20、 0、 20、 40°C与80°C条件下,F2311包覆可明显提高CL-20的临界撞击能与临界摩擦载荷;在-40℃环境下,包覆对CL-20临界撞击能与临界摩擦载荷无影响,原因可能与包覆材料的玻璃化转变温度有关;包覆后样品的实测爆热与爆速可达到5 612.03 kJ/kg和8 975.81m/s,与CL-20相比分别减小了8.70%和2.39%。研究结论对CL-20的安全储存、使用和高效能量输出具有一定的参考价值。     

制备方法对HNIW撞击感度影响研究进展

2,4,6,8,10,12-六硝基-2,4,6,8,10,12-六氮杂异伍兹烷(HNIW)是一种高能新型材料,目前已广泛应用于军事领域。由于HNIW在受到碰撞时容易发生剧烈化学反应,因此需要通过采用合适的材料制备方法来调控其撞击感度。综述了溶剂-非溶剂法、机械分散法及超临界流体法等多种方法制备得到的HNIW撞击感度研究进展,指出微观形貌和粒径尺寸是影响HNIW撞击感度的关键因素,小尺度球形化的HNIW具有更低的撞击感度。     

不同粒度及包覆改性高氯酸铵的热分解性能和安全性能研究

采用扫描电子显微镜和X射线衍射仪对不同粒度及包覆改性高氯酸铵(AP)颗粒的分散性及晶相进行了表征,并通过差示扫描量热法和机械感度测试研究不同AP样品的热分解性能和安全性能。结果表明,随着AP粒度增加,颗粒分散性得到一定改善,相同粒度的包覆改性AP分散性优于普通AP;不同粒度及包覆改性AP的晶相均一致;AP粒度越小,其热分解性能越好,对于粒度相同的AP,包覆改性对其热分解性能影响不大;随着AP粒度增加,其撞击感度和摩擦感度均降低,平均粒径(d_(50))分别为1μm、3μm和6μm的AP其撞击感度和摩擦感度分别为96%、80%、64%和28%、28%、16%;包覆改性可以明显降低AP的感度,d_(50)为3μm的包覆改性AP与粒度相同的普通AP相比,撞击感度和摩擦感度分别降低了28%和16%。     

高分子复合黏胶体系对CL-20包覆及性能的影响

为了降低CL-20的机械感度,选择聚丙烯酸酯橡胶（HyTemp）和聚氨酯（TPU）作为黏结剂,微晶蜡作为钝感剂,对CL-20晶体表面进行包覆,分别制备了CL-20/HyTemp/微晶蜡、CL-20/TPU/微晶蜡、CL-20/HyTemp复配TPU/微晶蜡3种样品。分别通过扫描电子显微镜（SEM）、X射线衍射仪（XRD）、X射线光电子能谱仪（XPS）、差示扫描量热仪（DSC）、机械感度仪来表征样品的表面包覆情况、晶体结构、热稳定性以及机械感度。结果显示:HyTemp、TPU和微晶蜡都能有效包覆CL-20;且3种样品中CL-20的晶型仍为ε型,未发生改变。与包覆前相比,3种样品中氮元素含量均有大幅度的降低,包覆程度较高。其中,高分子复合黏结剂（HyTemp复配TPU）包覆样品的表面更为紧凑密实。与原料CL-20相比,复合黏结剂包覆样品的表观活化能提高了164.45 kJ/mol,熵变和焓变也有较大提升,反应活性降低,热稳定性明显改善;临界载荷由原料CL-20的60 N提高到了288 N,撞击感度也比原料CL-20降低了3.6 J,降感效果显著。采用HyTemp复配TPU作为黏结剂包覆的样品综合性能最好。     

粉状改性硝酸铵感度特征试验研究

对粉状改性硝酸铵撞击感度、摩擦感度、雷管感度、静电火花感度、粉尘爆炸下限进行了测定.研究表明,同普通硝酸铵相比,改性硝酸铵具有较低的危险感度和良好的使用感度;在生产改性硝铵炸药过程中,当工业硝酸铵加入表面改性剂后,在满足工艺条件温度的情况下,应减少撞击和摩擦等机械作用.     

重结晶对PYX热性能和机械感度的影响

分别采用降温法和溶剂-反溶剂法对2,6-二苦氨基-3,5-二硝基吡啶（PYX）进行了重结晶研究。表征了不同重结晶方法所得PYX晶体的形貌和粒径,测定了重结晶前、后的晶体纯度,研究了重结晶对晶体热性能和机械感度的影响。结果表明:采用降温法在DMSO中得到的多为小颗粒团聚形成的不规则块状PYX晶体;采用溶剂-反溶剂法在DMF或DMSO中得到的多为片状PYX晶体,在DMSO/DMF混合溶剂中得到的多为规则的多边形块状PYX晶体。相比较而言,多边形块状PYX晶体的表面光滑度良好,粒径跨度最小,纯度最高,热稳定性较优,且兼具最低的撞击感度和摩擦感度,其热分解峰温和热爆炸临界温度较重结晶前分别提高了8.99 ℃和9.11 ℃,撞击感度和摩擦感度较重结晶前分别降低了16％和12％。     

2,4,6-三硝基苯甲硝胺感度标准物质的制备及均匀性检验

以工业2,4,,6-三硝基苯甲硝胺(特屈儿)为原料,采用热过滤和重结晶工艺,制备出了特屈儿感度标准物质.考察了搅拌和结晶温度等重结晶工艺对晶型和收率的影响,确定了较优化的条件为:用丙酮为溶剂,在50℃热过滤除去机械杂质,然后采用沉降法和间歇式搅拌结晶的方法,制备出了平均粒度(D50)为359.84μm的针状晶体.感度测试结果表明,所制备的特屈儿的撞击感度为46.92％,摩擦感度为13.2％,并具有较好的均匀性,已达到感度标准物质的技术指标要求.     

Study on ultrasound assisted precipitation of CL-20 and its effect on morphology and sensitivity

Applying ultrasound to crystallizing systems offers significant advantages for modifying and improving the processes as well as quality of products. This paper reports on ultrasound assisted reprecipitation of CL-20 to obtain fine particles as well as to achieve desired morphology, which will improve insensitivity characteristics. In this study, CL-20 has been reprecipitated by sonication process and has been characterized by DSC, SEM and particle size analysis. The results are compared with control CL-20 sample (unsonicated). SEM photographs revealed that sonication process offer uniform crystalline morphology without any agglomeration. The particle size of sonicated CL-20 sample obtained is around 5+/-1 microm with a narrow particle size distribution. The DSC thermogram of sonicated and unsonicated sample is identical. CL-20 samples were subjected to impact and friction sensitivity experiments, the results indicate the sensitivity characteristics reduced considerably. Ultrasonic assisted crystallization technique reduces the time of reprecipitation considerably with an enhanced recovery of CL-20 with a very narrow particle size distribution.     

氟橡胶包覆硝酸肼镍及其对雷管撞击感度的影响

利用水悬浮法将氟橡胶包覆在硝酸肼镍(NHN)表面制备出了NHN造型粉,并将其应用于基础雷管。通过DSC研究了NHN造型粉的热性能，测试了NHN造型粉的机械感度和火焰感度以及工业基础雷管的撞击感度和起爆能力。研究结果表明:氟橡胶包覆能够提高NHN的热稳定性，且热稳定性随着氟橡胶包覆量的增加而提高；NHN造型粉的机械感度均低于原料NHN，当氟橡胶包覆量（质量分数）为9%时，撞击感度下降幅度明显，可达142.9%；NHN造型粉用在基础雷管中做起爆药，可以降低基础雷管的撞击感度并保持其起爆能力。     

Emulsion synthesis of CL-20/DNA composite with excellent superfine spherical improved sensitivity performance via a combined ultrasonic–microwave irradiation approach

An advanced emulsion method was developed via combined ultrasound-microwave irradiation and utilized for the crystallization of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) and 2,4-dinitroaniline (DNA) spherical composite, which had been successfully fabricated with molar ratio of 1:1, The morphology and structure of the products were fully characterized using field emission scanning electron microscopy, powder X-ray diffraction, Fourier transform infrared spectroscopy. The thermal stability of micro structure was closely investigated via differential scanning calorimetry, and sensitivity performance was tested. The results suggested that the surface of particle was glazed while particle with narrow size distribution were produced. Remarkably, the drop height of 50% explosion probability data showed insensitivity compared to the previously reported energetic composites, which data was up to 57.8 cm. Besides, some experimental conditions including the amount of surfactant gelatin (0–1.2 wt% of accounting for the mass of CL-20) and standing time were examined. It was found that the greater the concentration of surfactant, the more conducive to the formation of emulsion, and standing time had a dramatically significant effect on the particle size. Summarily, the present process involving an initial powder made it possible to obtain micro spherical composite with ideal impact sensitivity, compared to those produced by conventional methods.     

Prospective Validation of High-Shear Wet Granulation Process by Wet Granule Sieving Method. I. Selection and Characterization of Sieving Parameters for Wet Granules

To characterize the progression of high-shear wet granulation for various drugs and formulations based on the particle size distribution of wet granules during granulation, a general sieving method for wet granules was investigated. Wet granulation was conducted in a 25-liter high-shear mixer using four model drugs with different solubilities and particle sizes (ethenzamide, unmilled and milled acetaminophen, and antipyrine). Because of its small size and efficient sifting mechanism, a sonic sifter was used to determine the wet granulation particle size distribution. From the good correlation of particle size distribution between wet granules and dry-sized granules, an intensity of 80% of full-scale amplitude and a sieving time of 3 min were selected as wet granule sieving parameters. 7% general sieving method showed good measurement precision as long as the determination was completed within 20 min after sampling, Further, the method was independent of sampling position within the mixer chamber.     

激光粒度分析和筛分法测粒径分布的比较

分别采用筛分法和马尔文激光粒度分析仪两种方法对16种颗粒的粒径分布进行了测量。通过比较,发现两种测量手段得到的粒径分布结果存在较大的差异,马尔文激光粒度方法对颗粒粒径的测量结果偏小,受颗粒形状的影响很大;筛分法对微细颗粒的测量误差较大,但对大粒径颗粒的测量较为准确。通过对不同粒径段灰颗粒的显微照相,发现细颗粒的团聚是筛分法测量小颗粒结果偏小的主要原因。