包覆硝酸铵发射药吸湿性和安定性研究

为研究包覆硝酸铵(AN)发射药的吸湿问题,用硝化棉(NC)对不同AN含量的AN发射药进行了不同层数的包覆,然后对未包覆和包覆试样进行了平衡干燥器法吸湿测试和真空安定性试验。结果表明:在温度为30℃、相对湿度为90%的条件下,AN发射药的吸湿量随着AN含量的增加而增加;包覆层有效抑制了吸湿性,提高了AN发射药的安定性。     

包覆硝酸铵发射药界面力学性能研究

研究包覆硝酸铵发射药的界面力学性能。采用拉伸剪切和压缩的方法测定在不同硝酸铵含量、不同硝酸铵粒径、不同温度下包覆硝酸铵发射药的界面剪切强度。实验结果表明,随着硝酸铵含量的升高,发射药的界面剪切强度先上升再下降;随着硝酸铵粒径的降低,发射药的界面剪切强度不断下降;随着温度的升高,发射药的界面剪切强度先升高再降低。     

单基硝酸铵发射药的能量及燃烧性能

单基硝酸铵发射药已实现了洁净燃烧,为进一步研究其应用价值,从理论上计算了单基硝酸铵发射药的能量示性数。通过静态燃烧实验研究其燃烧性能,并用弹道试验检验其在某口径火炮上的适用性,结果表明其满足该火炮的内弹道指标要求。     

硝酸铵发射药力学性能的研究

研究硝酸铵对发射药力学性能的影响。采用拉伸实验方法,测定不同硝酸铵含量、粒径下发射药的拉伸强度、伸长率、应力-应变曲线。结果表明,随着硝酸铵含量的升高,发射药的拉伸强度、伸长率、回弹模量、韧性模量先降低、再升高、后降低;在硝酸铵含量较低时,随着硝酸铵粒径的减小,发射药的拉伸强度升高;硝酸铵在发射药中形成次级结构,使其粒...     

含硝酸铵发射药内弹道过程数值模拟

通过分析不同硝酸铵含量的发射药的能量示性数,在φ30 mm火炮装填条件下,采用传统的经典内弹道模型,模拟计算出不同硝酸铵含量的七孔火药发射药的膛压、弹丸初速等弹道参数,研究硝酸铵含量对硝酸铵发射药内弹道参数的影响。结果表明,随着硝酸铵含量的增加,膛内压力和弹丸速度先增加后降低,硝酸铵含量存在一个最优点使二者达到最大值。     

改性单基发射药热行为和力学性能的研究

为了改善改性单基发射药的燃烧性能和力学性能,通过差示扫描量热法、真空安定性试验和甲基紫试验,研究了6种改性单基发射药的热分解过程和热安定性,并测试了其冲击和压缩性能,分析了硝化纤维素含氮量和硝基胍含量对改性单基发射药热行为和力学性能的影响。结果表明,随着硝基胍含量的增加,改性单基发射药的的热分解峰温和热安定性逐渐提高,力学性能逐渐降低;随着硝化纤维素含氮量的降低,改性单基发射药的热分解峰温和热安定性逐渐升高,力学性能逐渐增加。     

改性单基发射药热行为和力学性能的研究

为了改善改性单基发射药的燃烧性能和力学性能,通过差示扫描量热法、真空安定性试验和甲基紫试验,研究了6种改性单基发射药的热分解过程和热安定性,并测试了其冲击和压缩性能,分析了硝化纤维素含氮量和硝基胍含量对改性单基发射药热行为和力学性能的影响。结果表明,随着硝基胍含量的增加,改性单基发射药的的热分解峰温和热安定性逐渐提高,力学性能逐渐降低;随着硝化纤维素含氮量的降低,改性单基发射药的热分解峰温和热安定性逐渐升高,力学性能逐渐增加。     

废旧单基药爆轰性能的实验研究

采用简单易行的见证板试验研究了单基药的爆轰性能。实验结果表明,9／7单基药自由装填可正常起爆,经钝感后爆轰感度下降,自由装填后爆轰不完全,用硝酸铵胶液填充后可改变其爆轰性能;5／7粒状单基药包覆和填充前后的爆轰性能与9／7单基药相同,22／1单基管状药填充前后爆轰性能可以由不完全变为完全;得到单基药爆轰性能可控制的结论,并且装药药型和装药量对爆轰性能也有影响。     

甲基紫试验在长贮火药安定性检测中的应用

为确定甲基紫在长贮火药安定性检测中的可靠性,对选定的经过85℃老化试验的单基药、双基药、三基药试样,分别进行134．5℃和120℃甲基紫试验。用化学分析法测定了安定剂的含量,用方差检验法分析了甲基紫试验中的试纸变色时间和发射药中安定剂含量随老化时间的变化关系。结果表明,单基发射药、双基发射药、双基改性推进剂的甲基紫试纸变色时间随老化时间的变化显著,双基推进剂和三基发射药甲基紫变色时间随贮存时间的变化不显著。     

RDX基发射药相容性和安定性的研究

为了解由黑索今(RDX)、聚氨酯黏合剂、硝化棉等组分组成的发射药的相容性和安定性,采用差示扫描量热法(DSC)进行测定。根据不同加热速率下的峰温,进而求得加热速率趋于零时试样的峰温TP0、单独体系相对于混合体系分解峰温的改变量ΔTP及表观活化能改变率ΔE:Ea,考察了不同单独体系下的发射药的相容性和安定性。研究结果表明,以单基发射药作为单独体系,新型发射药的相容性较好;以RDX或聚氨酯作为单独体系,新型发射药的相容性均较差;新型发射药的安定性低于RDX,高于硝化棉。     

非均相发射药界面研究进展

为了提高发射药能量,通过向发射药中添加一些固体含能颗粒,形成非均相发射药结构。相与相间界面在很大程度上影响发射药的力学性能进而影响其燃烧性能等。对非均相发射药的界面结构及界面张力(黏附功)在非均相发射药研究中的应用进行了综述。     

Effect of polymer coating on ammonium nitrate substrate

Prilled, spheroidized, and granular ammonium nitrates (AN) were coated with poly(chloro-p-xylylene) (parylene C) by a vapor deposition polymerization technique. Particles of AN with a 0.2% coating remain free flowing after long exposure to ambient conditions. The effectiveness of the coating as a moisture barrier on the three forms of AN was found to be in the order spheroids > prills > granules. Water adsorption isotherms and hygroscopicity determinations indicate that a 0.7% coating hydrophobes the surface of AN by approximately one order of magnitude. The parylene C/AN interface exhibits chemical and physical stability at elevated temperatures.     

结晶亚硝酸钠混入对乳化炸药安全性的影响

为了研究结晶状敏化剂意外混入乳化炸药中的危险性，采用杜瓦瓶恒温试验法研究结晶状亚硝酸钠对硝酸铵、乳胶基质和乳化炸药热稳定性的影响。试验结果表明，在400 g样品中添加10 g亚硝酸钠的试验条件下，混合体系热稳定的临界温度范围分别为：硝酸铵40～45℃，乳化炸药45～50℃，乳胶基质则大于100℃。硝酸铵、乳化炸药和乳胶基质中的结晶亚硝酸钠临界添加量分别< 1 g，2 g和10 g。可见样品体系热稳定性：硝酸铵< 乳化炸药< 乳胶基质。样品含水量的增加可提高混有亚硝酸钠样品混合体系的热稳定性。     

微胶囊技术在硝酸铵改性中的应用

提出了用聚苯乙烯包覆硝酸铵制备硝酸铵微胶囊的新方法 ,采用电子能谱仪研究了包覆效果 ,并对包覆前后的硝酸铵进行吸湿性测量 ,分析了改性后的硝酸铵吸湿结块性降低的原因和机理。     

Acrylonitrile/vinyl acetate copolymer nanofibers with different vinylacetate content

In this study, free radical copolymerization of acrylonitrile (AN)–vinyl acetate (VAc) was performed for five different feed ratio of VAc (wt %) by using ammonium persulfate (APS) in the aqueous medium. The effect of VAc content on the spectrophotometric and thermal properties of AN–VAc copolymers was investigated by Fourier Transform Infrared–Attenuated Total Reflectance spectrophotometer (FTIR–ATR), differential scanning calorimeter (DSC), and thermal gravimetric analyzer (TGA). Thermal stability of homopolymer of AN is improved after being copolymerized. The electrospun P(AN‐co‐VAc) nanofibers were fabricated and the effect of VAc content on the morphologic properties of nanofibers was studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The viscosity of the solution had a significant effect on P(AN‐co‐VAc) electrospinning and the nanofiber morphology. The average diameters of P(AN‐co‐VAc) nanofibers decreased 3.4 times with increasing feed ratio of VAc wt %. The P(AN‐co‐VAc) electrospun nanofiber mats, with the feed ratio of 30 wt % VAc, can be used as a nanofiber membrane in filtration and as a carbon nanofiber precursor for energy storage applications due to high surface to volume ratio, high thermal stability, homogeneous, and thinner nanofiber distribution. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

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。     

Morphology of hybrid coatings based on polyester, melamine resin, and silica and the relation with hardness and scratch resistance

The morphology of hybrid coatings based on polyester, melamine resin, and various amounts of silica has been investigated, and the hardness and scratch resistance were determined. By increasing silica content, an increase of silica particles in size and number was observed. Small silica particles were preferentially present at the surface. The influence of the silica content on the K?nig hardness, indentation hardness, and elastic modulus was minor. The improved scratch resistance determined for a hybrid coating with 11.4 wt% silica, compared to a similar organic coating without silica, was attributed to small silica particles preferentially present at the surface. Presented at the 26th International Waterborne, High-Solids, and Powder Coatings Symposium, February 10–12, 1999, New Orleans, LA. Dept. of Polymer Chemistry and Coatings Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands. Materials Division, Dept. of Materials Chemistry and Coatings, P.O. Box 595, 5600 AN Eindhoven, The Netherlands.