提高改性单基药燃烧性能的研究

为了改善改性单基药的燃烧渐增性、提高初速,通过加入添加剂对改性单基发射药的制备工艺进行了改进。用显微红外光谱测定了发射药中功能组分的含量分布,用密闭爆发器和内弹道试验研究了发射药的燃烧性能。结果表明,加入添加剂后,发射药中硝化甘油NG的渗透深度由270μm增加到360μm,浓度最大值对应的深度由110μm增加到180μm;钝感剂NA聚酯的渗透深度由270μm增加到360μm。燃烧渐增性明显增强,燃烧渐增因子Pr由0.363 0提高到0.445 0。其装药的内弹道性能得到显著改善,初速提高3.1%,动能提高6.3%,装填密度从0.921 g/cm3提高到0.949 g/cm3,具有高装填密度、高燃烧渐增性、高初速的优点。     

发射药导热系数测定的影响因素

利用热流法导热系数测定仪测量了不同实验条件下双基发射药的导热系数。分析了试样高度、真空度及硝化甘油含量对测量结果的影响。结果表明,发射药试样的高度较低时,或测试过程中的真空度越高,导热系数测定值较接近其真空值。硝化甘油含量对发射药的导热系数有明显影响。     

成核剂对PP发泡行为和力学性能影响

采用化学发泡注射成型技术制备了发泡聚丙烯(PP)复合材料,研究了不同成核剂(NA)含量对其发泡行为和力学性能的影响。结果表明:NA的加入为泡孔成核提供了大量的成核位点,有效改善了发泡PP复合材料的泡孔结构、尺寸分布和泡孔密度;当NA质量分数为5‰时,发泡材料泡孔平均直径最小约125μm,泡孔密度最大约2.54×10~5个/cm~3,泡孔尺寸分布较好。另一方面,随着NA含量的增加,发泡PP复合材料的拉伸强度、弯曲强度和弯曲模量呈增加趋势。     

硅胶柱层析法分离提纯双基药中的硝化甘油

探讨了以双基药为原料,采用柱层析法分离提纯来获取少量硝化甘油的工艺方法。结果表明,以乙醚为提取溶剂、二氯甲烷为流动相,45~75μm的层析用粗孔硅胶为固定相,空塔流速约为0.764 cm/min的条件下进行层析柱分离提纯,可获取克量级的硝化甘油。经高效液相色谱法分析,所得硝化甘油纯度高,未见杂峰。     

恒温热分离称重法测定火药包覆材料有机玻璃中的硝化甘油

提出了一种试样无需分离，测定简便快速，称为恒温热分离称重法的测定火药包覆材料中硝化甘油含量的新方法，并应用于有机玻璃中硝化甘油浓度分布的测定。对于５ｍｇ的试样，当硝化甘油浓度为４０％－１％时，５次测定的标准偏差约为０．４％。不仅可用无ＤＴＧ的热天平，而且也可用其它常用热分析仪进行热分离，在与十万分之一的天平配合后，即能直接测定包覆材料中硝化甘油的含量。     

浸取/气相色谱法表征发射药中钝感剂的浓度分布

采用丙酮石油醚混合溶剂为浸取液浸泡发射药,用气相色谱测定不同时刻从发射药中浸取出来的樟脑,用浸取液中的樟脑浓度c与浸取时间t的关系曲线表征发射药中的樟脑浓度分布。重复实验结果表明,对同一发射药样品。在确定的浸取条件下,浸取曲线重复性一致,浸取曲线仅由发射药中樟脑的浓度分布来确定。实验结果表明,当樟脑的浓度分布变化时,浸取曲线也发生相应变化。因此,可以用浸取／气相色谱法来表征发射药中钝感剂樟脑的浓度分布。     

连续式提取法在硝基胍发射药成分分析中的应用研究

介绍连续式提取方法及该法用于硝基胍发射药中硝化甘油、中定剂及硝基胍等组分的提取分析研究。     

有机磷酸盐成核剂粒径对PP性能的影响

通过调控反溶剂法中的转速、反溶剂与溶剂配比、溶液浓度等条件制备了不同粒径的2,2’–亚甲基双(4,6–二叔丁基苯基)磷酸钠(NA–40)成核剂,考察了NA–40粒径对等规聚丙烯(i PP)力学性能的影响,并利用差示扫描量热(DSC)仪研究了NA–40粒径对i PP结晶性能的影响。结果表明,随着NA–40粒径的增加,NA–40对i PP力学性能的改善作用变弱。NA–40平均粒径为(17.7±2.2)μm时,i PP/NA–40–1的弯曲弹性模量、弯曲强度和拉伸强度与纯i PP相比,分别提高了44.5%,20.5%和8.3%,相应的缺口冲击强度有所降低;当NA–40平均粒径为(52.6±1.1)μm时,i PP/NA–40–4的弯曲弹性模量、弯曲强度和拉伸强度的增幅分别降至16.8%,2.3%和6.4%。在较低的降温速率下,NA–40粒径对结晶峰值温度(Tc)的影响不明显,提高降温速率对Tc的影响开始显现。用扫描电子显微镜观察NA–40形貌发现,NA–40呈棒状,加工过程影响NA–40粒径,但对NA–40形貌没有影响。利用偏光显微镜观察NA–40在i PP熔体中的分散性,粒径较小的NA–40能够均匀分散在i PP熔体中,而粒径较大的分散性差,大大降低了NA–40的有效成核浓度,影响了NA–40对i PP力学性能及结晶性能的改善作用。     

基于人工神经网络算法的发射药钝感剂浓度分布快速预测技术

提出一种适用于5/7改性单基发射药的快速预测钝感剂浓度分布情况的方法,基于人工神经网络算法构建了神经网络模型,然后使用已有的5/7改性单基发射药钝感剂浓度分布试验数据训练模型。结果发现,经过训练后模型输出的钝感剂浓度分布曲线和试验测定的钝感剂浓度分布曲线二者之间的复相关系数R高达0.93。这说明构建的模型可以较准确地快速预测出给定工艺参数条件下5/7改性单基发射药钝感剂浓度分布曲线,相较于传统的测试方法,具有省时、省力、方便快捷的优势,证明此方法具有很好的实用性。基于此模型还可以反向应用,根据需要的钝感剂浓度分布曲线来预测所需要的钝感发射药制备存贮工艺条件。     

一种三羟甲基乙烷三硝酸酯的制备方法(CN107619370A)

<正>西安近代化学研究所近日开发一种三羟甲基乙烷三硝酸酯(TMETN)的制备方法。TMETN是一种混合炸药、固体推进剂和发射药用新型不敏感液体含能增塑剂,与传统液体含能增塑剂硝化甘油相比,能赋予火炸药更好安全性能和工艺性能,是替代硝化甘油的较佳候选物。常采用     

NG含量对改性单基发射药燃烧性能的影响

以高氮量5/7单基发射药为基体药粒,通过先浸渍吸收NG、后吸收聚酯钝感剂NA的两步工艺制备出改性单基药,在制备过程中,NA含量恒定,浸渍NG的质量分数为5%、10%和15%,制备出3种NG含量的改性单基药样品RN-a、RN-b和RN-c。采用密闭爆发器试验和30mm弹道炮内弹道试验,研究了NG含量对改性单基药燃烧性能的影响。结果表明,所制备的3种改性单基药样品的燃烧渐增性均优于基体药;在保持最大膛压不增加的情况下,弹丸初速较5/7单基药装药分别提高36.9、91.7和57.4m/s。在制备工艺过程中,通过调节NG的含量,能够改善改性单基药的燃烧性能,实现大幅度提高炮口初速的目的。     

一种新型盐浴渗氮工艺对K55钢耐蚀性的影响

采用一种新型盐浴对K55石油管线钢进行盐浴渗氮处理,研究了渗层的截面形貌,显微硬度在不同渗层深度上的分布及渗层的耐硫腐蚀性。K55钢经560℃盐浴渗氮处理2h后,表层组织由疏松层、渗氮层及基体扩散层组成。渗层和表面的氧化疏松薄层的厚度分别约为12.48μm和1.54μm,渗层的总深度约为30μm。经渗氮处理的K55钢,其显微硬度明显提高,表面的显微硬度高达695HV,但显微硬度沿渗层深度方向急剧下降。渗氮处理后,K55钢的耐硫腐蚀性能得到明显改善。因此,可利用盐浴渗氮处理来降低油管下井前的腐蚀缺陷。     

一种新型聚酯钝感剂在发射药中的应用

采用水相钝感法工艺制备了含新型聚酯钝感剂的单基药和高能硝胺发射药,通过常规理化性能测试、密闭爆发器和加速长贮等实验研究了聚酯钝感剂对两种发射药性能的影响。结果表明,聚酯钝感剂与单基药和高能硝胺药相容性良好,具有挥发性小、抗迁移性能强等优点,能够显著提高单基药的燃烧渐增性;含聚酯钝感剂的发射药加速老化长贮实验前后,初速跳差小于10m/s,其内弹道性能几乎无变化。     

FT-IR study of melamine enrichment in the surface region of polyester/melamine film

Melamine enrichment in the surface regions of polyester/melamine films was studied by using Fourier transformation infrared spectroscopy, attenuated total reflection (ATR) method. A higher melamine/polyester mixing weight ratio of about 0.43 before curing gave a decreasing melamine concentration as a function of the distance from the film surface after curing, but a lower ratio of about 0.14 resulted in an almost no melamine enrichment at the surface and the highest concentration in an inner region. The degree of melamine enrichment estimated with a constant penetration depth in the ATR method strongly depended on the melamine/polyester mixing weight ratio and became maximum when the ratio was about 0.4 for films cured at 200°C. These results were qualitatively explained by a simple model where selective activation of the catalyst in the surface region leads to a concentration gradient of melamine molecules able to diffuse and the concentration gradient induces a melamine current from the inner portions towards the surface.     

Methylcentralite concentration profiles in monoperforated extruded nitrocellulose and nitrocellulose/nitroglycerine propellant grains by Raman microspectroscopy

Raman microscopy was used to determine the methylcentralite (MC) concentration profiles diffused into single-base (nitrocellulose) (NC) and double-based (nitrocellulose/nitroglycerine) (NC/NG) small-arms propellant grains. External and internal concentration profiles were determined by measuring the concentration of MC relative to the NC and NC/NG at 5-μm intervals into the grain from the edge inward and the perforation edge outward. The external profile was constant with a diffusion and interaction mechanism, i.e., a level concentration of deterrent through the outer region of the grain followed by a gradual dropoff in concentration with distance into the grains, whereas the internal profile was found to be dependent on perforation size with either a diffusion and interaction mechanism profile or a gradual decrease in concentration profile.     

内弹道稳定剂对中高燃速RDX-CMDB推进剂燃烧性能的影响

以一种中高燃速改性双基推进剂配方为基础配方,添加不同粒度的Al_2O_3及不同品种的内弹道稳定剂,研究了6~20MPa下推进剂燃速和燃速压强指数的变化规律,并对其燃烧机理进行了分析。结果表明,添加Al_2O_3后推进剂的燃速降低,且随着压强的升高,燃速降低的幅度减小;不同品种的内弹道稳定剂对燃速及燃速压强指数降低和提高的幅度不同,TiO2提高了推进剂高压段的燃速,MgO几乎不影响推进剂燃速,而Al_2O_3、ZrO_2均降低了推进剂的燃速。添加不同粒度的Al_2O_3后,均使燃烧表面的催化剂含量(浓度)降低,改变了催化剂的催化效率,从而导致添加芳香铅A催化剂的推进剂中Al_2O_3粒径分别为10μm和2.5μm时,燃速相应降低0.25mm/s和1.25mm/s。不同品种的内弹道稳定剂对燃烧表面催化剂含量、分散均匀性、催化活性的影响不同,TiO_2、MgO的活性高于Al_2O_3和ZrO_2,从而表现出添加TiO_2、MgO的推进剂燃速高于添加Al_2O_3、ZrO_2的推进剂。     

Surface inhibition of double base rocket propellants with photocurable unsaturated esters

Inhibition of a double base propellant surface with a good percentage of nitro bodies in the propellant composition is a rather difficult process. One of the methods of inhibiting the surface is to use unsaturated polyesters with free radical cure having high exotherm as a barrier coating. This system has been improved by using a 1:1 mix of photocurable vinyl ester with pendant —OH groups and unsaturated polyester that underwent room temperature free radical cure. Adhesion of the barrier coat to the propellant surface through its —OH groups was stronger than the propellant strength itself. Additional layers of commercially available unsaturated polyester could be easily grafted on to the barrier coat through chemical cure.     

Diffusion of deterrents into a nitrocellulose-based small arms propellant. The effect of deterrent structure and solvent

The depth of penetration of five urea-based deterrents and of dinitrotoluene into an extruded monoperforated nitrocellulose propellant has been studied. The depth of penetration is directly proportional to the concentration of the deterrent solution. Structural variation of the urea-based deterrents and increasing the water content of the alcoholic deterrent solutions have significant effects on the depth of deterrent penetration. Dinitrotoluene penetrates more rapidly than the urea deterrents in all solvents studied. The results are consistent with a diffusion with interaction mechanism. It is suggested that some previous evidence for such a mechanism was not definitive.     

An infrared microspectroscopy method for determining deterrent penetration in nitrocellulose-based propellant grains

Infrared microscopy was used to determine di-n-butyl phthalate, dinitrotoluene, and methyl centralite diffusion profiles in cross sections of nitrocellulose-based propellant grains. Absorbance of marker functional groups was determined at 25–50 µm intervals from the edge to the center of the sections. Comparison of IR and light microscopical data indicated that the optically visible boundary does not define the entire depth of deterrent penetration into propellant grains.