黏合剂和钝感RDX对ETPE发射药流变性能的影响

以不同Mn(数均相对分子质量)的ETPE(含能热塑性弹性体)为黏合剂、不同粒度的RDX(黑索今)为含能添加剂,制备了一种PBX(聚合物粘接炸药)——ETPE发射药。研究结果表明:ETPE发射药的表观黏度(η)随剪切应力和温度的升高而降低,较高的压力和温度有利于发射药的流动变形,加工温度以90~95℃为宜;当温度和RDX粒度相同时,ETPE的Mn越小,ETPE发射药的η越低;当温度和ETPE的Mn相同时,RDX的粒度越大,ETPE发射药的η越低。     

ETPE发射药的热分解特性与燃烧机理

通过DSC、PDSC分析了点火延迟时间长及难点火ETPE发射药燃烧过程中的热分解特性。用中止燃烧实验装置、SEM电镜观察研究了ETPE发射药燃烧表面的形貌变化及燃烧规律。结果表明,ETPE发射药热分解过程主要由其配方中含能添加剂RDX的热分解过程决定,RDX组分与含能黏结剂BAMO/AMMO聚合物体系之间的燃烧不同步性是造成ETPE发射药点火燃烧性能不佳的主要原因。根据ETPE发射药燃烧过程的特点,归纳出该类发射药的燃烧机理。     

GAP-ETPE基发射药配方的能量特性分析

采用内能法计算了GAP含能热塑性弹性体(ETPE)为基的多个发射药配方的能量特性参数.结果表明,RDX/ETPE/A3发射药的火药力约为1 170 kJ/kg,用CL-20、TNAZ等替代配方中的RDX,火药力呈线性规律变化,并且能够得到1 300 kJ/kg以上的火药力.不同的含能增塑剂对配方的能量有很大的影响,含BTTN、BuNENA发射药配方具有很高的能量,RDX/ETPE/NC/BTTN(ETPE与NC的质量比为70∶30)发射药配方的火药力在较宽的范围内都可以达到1 200 kJ/kg.     

溶剂含量对变燃速发射药的流变性影响研究

用MLW-90防爆流变仪测试不同溶剂含量下变燃速发射药内、外层的流变性能.得出结论,随着溶剂含量的增加,其表观黏度降低,流动性增强;乙基硝化纤维素(EC)、黑索今(RDX)的加入降低了变燃速发射药的表观黏度.     

ETPE发射药等离子体点火的燃烧特性

为解决ETPE发射药点火延迟时间长及难点火的问题,用高功率脉冲电源通过等离子体发生器产生电弧等离子体点燃ETPE发射药,并研究了ETPE发射药在等离子体作用条件下的点火燃烧特性.结果表明,与常规点火方式相比,等离子体作用使ETPE发射药的燃速显著增强,点火延迟期缩短,点火的一致性改变.分析认为,等离子体高温高速射流的强作用使得RDX颗粒快速越过吸热熔融过程达到分解放热阶段,所以ETPE发射药点火延迟期缩短以及燃烧初期燃速提高.     

空气电弧等离子体作用下发射药的燃烧特性

为了研究发射药等离子体点火作用机理,用扫描电子显微镜研究了不同强度电弧放电等离子体揭示的3种制式发射药及新型ETPE发射药在等离子体作用后的燃烧表面变化规律,得到等离子体点火后发生燃烧反应的质量.结果表明,电弧等离子体输入电能对发射药的点火有着重要影响,随着输入电能的增加,参加反应的发射药质量逐渐增加.ETPE发射药燃烧表面与常规制式发射药燃烧表面有较大差别.发射药对电弧等离子体的相对敏感程度不同,双基发射药最强,ETPE发射药最弱.     

黑索今基发射药热分解动力学研究

利用失重法(TG)在升温速率5 K·min~(-1)、10 K·min~(-1)、20 K·min~(-1)下对RDX基发射药的热分解进行了测试,并对其热分解动力学进行了研究。实验结果表明:将TG数据与Malek法相结合,利用辅助函数y(α)和z(α)判定RDX基发射药热分解动力学机理函数,通过动力学表达式的求解可以得出两种不同配方发射药的表观活化能及反应级数。     

NGu对含RDX硝胺发射药燃烧性能的影响

为从微观的角度研究NGu对含RDX的硝胺发射药燃速压力指数改变的影响,采用改进的小型点火燃烧模拟装置,在35MPa左右对几种发射药进行低压中止燃烧实验.通过SEM电镜观察发射药在低压下燃烧的表面状况.结果表明,在硝胺发射药的燃烧过程中,NGu在燃烧表面形成较厚的熔融层,抑制了RDX的爆燃;RDX的爆燃与燃烧表面熔融层之间的"均衡状态"影响发射药燃速压力指数的变化,当RDX与NGu质量比小于1时,燃速压力指数明显降低;当RDX和NGu同时存在时,发射药的燃烧表面有针状晶体生成.     

含RDX、CL-20的高能发射药的安定性研究

提高发射药的能量及其利用率是未来发射药技术研究的主要发展趋势,为了了解加入RDX、CL-20提高发射药能量的同时对其安定性产生的影响,采用差示扫描量热测试法,对三种不同配方的高能发射药的试验获得的数据进行处理与分析,讨论其安定性。对比三种试样,在RDX和CL-20比例减少、聚氨酯比例增加的情况下,发射药的安定性有轻微提升;影响发射药安定性的主要因素是发射药各组分的相互影响及配方比例的差异。从试验数据Tp0可以看出,混合体系A1、A2和A3间差异并不是很大,均在184~185℃之间。由DSC实验数据可得高能发射药安定性顺序为:A2A1A3。     

含RDX高能硝胺发射药的热分解动力学补偿效应

为了解高能硝胺发射药的热分解特性和动力学补偿效应,用高压DSC测试了含5组16种发射药的热分解行为,通过Kissinger方程获得了双基药和含RDX高能硝胺发射药的热活化能(Ea)和指前因子(A),讨论了其动力学参数的补偿效应。结果表明,含RDX高能硝胺发射药配方中的NC/NG和RDX的热分解反应动力学参数间存在动力学补偿效应,说明NC/NG和RDX的热分解反应分别有各自不同的反应过程或者由各自不同的速度决定步骤,不受配方中其他组分的影响。     

Polymer Nanocomposites from Energetic Thermoplastic Elastomers and Alex®

Polymer Nanocomposites (PNs) obtained from linear energetic copolyurethane thermoplastic elastomers (ETPEs) based on GAP and a commercially available nanometric aluminum (Alex) were characterized. Two methods were performed to prepare the PNs: in‐situ and by solvent evaporation. The thermal and mechanical properties of the pure ETPEs, of the composite ETPE/Al (micrometric) and of the nanocomposite ETPE/Alex were studied. The percentage of Alex was adjusted to obtain the optimum mechanical properties. The beneficial effects of the nanopowder on the material properties are highlighted. The introduction of nanoaluminum improves the elasticity and strength of the original ETPE and, consequently, makes it easier to use, to handle, and to process. It indicates that PNs can be considered for future applications in energetic material, such as in gun propellants, rocket propellants and insensitive melt‐cast explosive formulations.     

Review on Energetic Thermoplastic Elastomers (ETPEs) for Military Science

Energetic thermoplastic elastomers (ETPE) are futuristic binders for propellant/explosive formulations. Various aspects of ETPEs are addressed in this review. Synthesis modes of different copolymers for ETPEs are discussed. Attention is also given to formulations and thermal studies of ETPE‐based propellants and explosives. Processing methods and parameters of composition are included. As the cost and environmental concerns are prime factors of future generation propellants/explosives, the recovery and reprocessing methods are also briefly discussed.     

Effect of nitrocellulose (NC) on morphology,rheological and mechanical properties of glycidyl azide polymer based energetic thermoplastic elastomer/NC blends

As a new kind of propellant binder, energetic thermoplastic elastomer (ETPE ) can improve propellant recyclability and environmentally friendly disposal. The rheological behavior of the ETPE binder can be beneficial to identify suitable and safe conditions for processing ETPE propellants. In this paper, ETPE /nitrocellulose (NC ) blends with different mass ratios of NC to ETPE were prepared by the physical mixing method. The heat of explosion and the morphological, thermal, mechanical and rheological properties of the resulting blends were studied systematically. It was found that the heat of explosion of ETPE /NC blends increased with increasing NC content. SEM images showed that the NC domains in the blends changed from tiny pieces to fibers with increasing NC mass ratio, which indicates phase separation in the blends. The tensile mechanical properties of the blends had a peak value when the NC content was 10 wt%, and then increased with the increasing addition of NC . The thermal behavior made clear that the ETPE and NC were partially miscible. Rheological studies on dynamic strain sweep and frequency sweep demonstrated that the content of NC in the blends had a monotonic effect on their rheological properties at 130 °C. Rheological studies also showed that the rheology of the blends is dependent on temperature. The Cole ? Cole and Han plots confirmed phase separation in the blends. © 2016 Society of Chemical Industry     

等离子体对发射药烧蚀作用的机理研究(英文)

为了研究等离子体对发射药的点火燃烧作用机理,在Keidar教授处理烧蚀问题的双层动力学模型基础上,建立了用于描述等离子体对发射药烧蚀作用的物理模型和数学模型。研究了等离子体对SF-3发射药、GR5发射药及新型ETPE发射药的烧蚀作用,利用所获得的电弧等离子体特性参数与发射药的特性参数对烧蚀质量进行了数值模拟。结果表明,在较低的电弧等离子体能量作用下,理论计算结果与实验结果具有较好的一致性,所建立的模型能够反映等离子体对发射药的烧蚀作用过程。随着等离子体能量的升高,理论计算结果与实验结果之间的偏差逐渐加大,反应作用因素影响增强。3种类型发射药中,ETPE发射药对电弧等离子体的敏感程度最弱,SF-3发射药对电弧等离子体的敏感程度最强。     

Numerical Solution of the Flow of Power‐Law Gel Propellants in Converging Injectors

The governing equations of the steady, incompressible, isothermal, laminar flow of a power‐law, shear‐thinning gel propellant in a converging injector were formulated. The equations were transformed to a ψ–ω system, then discretized and solved. A numerical algorithm was developed for the solution of the flowfield. A parametric investigation was conducted to evaluate the effect of the injector geometry and the flow rate on the velocity and viscosity fields, for various gel propellants. In comparison to a straight injector, a convergent one can produce additional decrease in the mean apparent viscosity of the fluid. The mean apparent viscosity decreases significantly with increasing the convergence angle of the injector. In general, increasing the gel flow rate results in a decrease of the mean apparent viscosity of the fluid. Increasing the gellant content of gel propellants results in an increase of the fluid viscosity that decreases when the gel flows through the injector. Gels of different gellant content that flow through the same geometry injector exhibit similar relative reduction in viscosity.     

局部阻燃火药在模块装药中的作用

通过定容燃烧实验比较了含局部阻燃火药的模块装药中各装药组分及其混合装药的燃烧性能。结果表明,定容燃烧实验中局部阻燃火药的混合装药p-t曲线拐点处的相对已燃烧部分Ψe值随装填密度的变化而变化。通过不同装填密度的混合装药中止实验,分析了Ψe值变化的原因。由势平衡理论结合实验数据分析表明,Ψe值变化与实际模块装药火炮内弹道p-t曲线上势平衡点的相对已燃烧部分ΨE值变化相对应。在模块装药中,局部阻燃火药能起到调节膛压的作用。     

GAP基热塑性弹性体的合成与表征

以聚叠氮缩水甘油醚(GAP)、亚甲基二苯基二异氰酸酯(MDI)、1,4-丁二醇(BDO)为原料,采用两步法合成了一种GAP基的含能热塑性弹性体(ETPE).用差示扫描量热(DSC)、傅里叶变换红外光谱(FT-IR)、热失重(TG)和万能材料拉伸机等对ETPE进行了表征.结果表明,ETPE具有良好的低温性能和热稳定性,高...