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。     

复合固体推进剂用键合剂的研究进展

键合剂是改善黑索金(RDX)、奥克托金(HMX)等硝胺和氧化剂填料与黏合剂间界面作用的关键功能材料,也是提高推进剂力学性能的有效、方便、实用的策略。综述复合推进剂中硼酸酯(BEBA)与中性聚合物(NPBA)等键合剂的研究进展,归纳了键合剂的作用机理,梳理了当前和未来高性能推进剂用键合剂的发展动向,针对不同的黏合剂体系和新的固化方式等发展趋势,设计具有多种功能基团的键合剂结构,积极开发可同时与硝胺、氧化剂及黏合剂相匹配的键合剂,进一步完善补充键合机理,以满足高新武器系统对高力学性能推进剂的需求。     

温度对RDX/PET/NPBA推进剂药浆流变特性的影响

为获得温度对RDX/PET/NPBA推进剂药浆流变特性的影响,采用稳态和动态流变学方法测试了不同温度下RDX在硝酸酯增塑的PET黏合剂药浆中的黏度,研究了其流变特性随温度的变化规律。结果表明,当实验温度低于53℃时,RDX/PET/NPBA药浆黏度随温度的升高快速降低;高于53℃时,降幅变缓;当温度为57~60℃时,药浆黏度处于相对平稳状态。温度升高引起RDX/PET/NPBA药浆黏度的变化与黏合剂基体、RDX溶解度及RDX与键合剂作用三者之间均有关联。同时从RDX/PET/NPBA胶片实验结果得出,温度升高后胶片的力学性能提高,表明温度对键合剂的作用影响较大。     

HTPB/Al/AP/RDX复合推进剂组元之间相互作用研究

为了探索HTPB/Al/AP/RDX复合推进剂组元之间的相互作用,用DSC和TG-DTG方法以及分解反应动力学计算研究了递增组元的4个混合体系(包括HTPB黏合剂体系、HTPB/Al、HTPB/Al/AP和HTPB/Al/AP/RDX推进剂体系)中各组元之间的相互作用。结果表明,DTG峰温以及反应速率常数k可以表征各组元之间的相互作用,其DSC和TG过程可以分为3个阶段;除Al外,各组元之间存在相互作用,各阶段的质量损失测定值与按组分含量计算的加合值吻合得相当好,表明各组元并没有明显的跨阶段分解;AP与HTPB黏合剂的分解温度区间接近或部分重叠,在HTPB/Al/AP和HTPB/Al/AP/RDX的混合体系中发生了强烈氧化还原作用:四组元体系中RDX在200℃及220℃的速率常数k分别为1.53和6.81s-1,均大于单质RDX在同一温度下的速率常数1.33×10-6和1.06×10-5s-1,说明AP可以加速RDX的分解,但RDX对AP或(AP+HTPB)分解的影响呈现复杂的情况,由于HTPB/Al/AP和HTPB/Al/AP/RDX两体系中AP与HTPB的共同分解过程中存在“等动力学点”(308.0℃),温度低于此点时(AP+HTPB)分解速率常数k因RDX存在而下降,而当温度高于此点时则该k值因RDX存在而增大。通过RDX分解机理解释了存在这种现象的原因。     

HTPB/Al/AP/RDX复合推进剂组元之间相互作用研究

为了探索HTPB/Al/AP/RDX复合推进剂组元之间的相互作用,用DSC和TG-DTG方法以及分解反应动力学计算研究了递增组元的4个混合体系(包括HTPB黏合剂体系、HTPB/Al、HTPB/Al/AP和HTPB/Al/AP/RDX推进剂体系)中各组元之间的相互作用。结果表明,DTG峰温以及反应速率常数k可以表征各组元之间的相互作用,其DSC和TG过程可以分为3个阶段;除Al外,各组元之间存在相互作用,各阶段的质量损失测定值与按组分含量计算的加合值吻合得相当好,表明各组元并没有明显的跨阶段分解;AP与HTPB黏合剂的分解温度区间接近或部分重叠,在HTPB/Al/AP和HTPB/Al/AP/RDX的混合体系中发生了强烈氧化还原作用:四组元体系中RDX在200℃及220℃的速率常数k分别为1.53和6.81s~(-1),均大于单质RDX在同一温度下的速率常数1.33×10~(-6)和1.06×10~(-5)s~(-1),说明AP可以加速RDX的分解,但RDX对AP或(AP+HTPB)分解的影响呈现复杂的情况,由于HTPB/Al/AP和HTPB/Al/AP/RDX两体系中AP与HTPB的共同分解过程中存在"等动力学点"(308.0℃),温度低于此点时(AP+HTPB)分解速率常数k因RDX存在而下降,而当温度高于此点时则该k值因RDX存在而增大。通过RDX分解机理解释了存在这种现象的原因。     

一种判定RDX热分解机理函数与热安全性的方法

将DSC、TG数据与Malek法相结合研究了RDX的热分解,得到外延起始温度Le0、拐点温度T、峰顶温度Tp、分解终止温度Tf、分解焓变ΔH、表观活化能E、指前因子A、反应级数n、热爆炸临界温度Tb和自加速分解温度TSADT;利用TG热分析得到RDX热分解的起始分解温度T0、质量损失Δm%、最大质量损失速率及对应的温度...     

十二氢十二硼酸盐与推进剂组分的相容性

采用感度测试仪、密度分析仪和热重分析仪对3种十二氢十二硼酸盐:十二氢十二硼酸钾(BH-1),十二氢十二硼酸双N-甲基乌洛托品盐(BH-2)和十二氢十二硼酸双三氨基胍盐(BH-3)的物理性质进行了研究;并采用差示扫描量热仪对3种十二氢十二硼酸盐与4种常见推进剂组分(黏合剂、交联剂、增塑剂和高能填料)的相容性进行了研究。结果表明,3种十二氢十二硼酸盐密度均为1.2g/cm3,且对撞击和摩擦较为钝感;在500℃以下,3种十二氢十二硼酸盐与黏合剂(HTPB和PET)、固化剂(N-100和TDI)和增塑剂(DOS和A3)相容性好,但十二氢十二硼酸盐/RDX二元混合物分解反应峰温比各单独化合物的分解反应峰温降低12.7~37.5℃,会引发RDX和样品的提前分解,BH-2和BH-3与AP相容性较差,不适于在此类推进剂中使用。     

少烟NEPE推进剂的表面和界面性能

根据表面和界面化学原理,应用动态接触角测量仪和表面-界而张力仪测试了少烟NEPE推进剂的黏合剂体系(PNT)、填料(HMX、AP和Al粉)和键合剂的表面和界面性能.结果表明,填料(HMX、AP和Al粉)与黏合剂体系(PNT)的界面张力(γsl)大小顺序为:γAl/PNT＜γAP/PNT＜γHMX/PNT,填料与黏合剂体系的黏附功(Wa)大小顺序为:Wa(Al/PNT)＞Wa(HMX/PNT)＞Wa(AP/PNT);键合剂能够自发吸附和分散在推进剂的填料(HMX、AP和Al粉)表面和黏合剂体系中;在推进剂制备过程中,键合剂吸附于填料表面形成的界面能够稳定保持在黏合剂体系中;键合剂能明显提高推进剂的强度和模量,改善填料颗粒与黏合剂体系的界面粘结性能,这与表面性能测试结果一致.     

键合剂对RDX与HTPB的界面改善作用

根据表面与界面化学的相关原理,采用DCAT21型动态接触角/表面张力仪测量了常用键合剂、RDX、HTPB在不同探针液体中的接触角,通过接触角计算键合剂、RDX、HTPB的表面自由能及其分量。并计算了键合剂-RDX、键合剂-HTPB界面之间的黏附功。通过扫描电镜观察添加不同键合剂后RDX与HTPB的黏接状态。由黏附功数据和扫描电镜的观察结果可以得出结论:键合剂LBA603对RDX-HTPB界面的改善作用最好。     

石墨双炔/RDX复合物的热分解性能

为探究石墨双炔(GDY)对RDX热分解性能的影响,采用液相法制备出GDY,对其进行扫描电镜(SEM)、透射电镜(TEM)、X光电子能谱(XPS)、热重(TG)、红外(IR)表征;采用物理混合法将不同质量分数的GDY与环三亚甲基三硝胺(RDX)复合,用差示扫描量热仪(DSC)测试其热行为,并用Kissinger和Ozawa法进行动力学计算;用热重/红外/质谱联用仪(TG/IR/MS)研究GDY质量分数为5%的复合样品的热分解机理;根据GJB772A-97,采用DSC法进行相容性分析;从热分解峰温和活化能角度,比较了不同炭材料对RDX热分解的影响。结果表明,升温速率10℃/min、GDY质量分数为5%时,RDX热分解峰温升高2.97℃,活化能降低10.75kJ/mol; TG/IR/MS研究表明,加入GDY后,主要气体产物种类没有发生改变,但是CH_2O和N_2O气体产物在较低的温度下即会产生,表明GDY的加入能够促进C—N键的断裂,从而促进RDX的热分解;相容性测试表明GDY与RDX不相容;相比纯RDX,石墨烯和多壁碳纳米管(CNT)使RDX的热分解活化能分别降低59.76kJ/mol和25.6kJ/mol,降低程度高于GDY,而富勒烯(C_(60))则使RDX的活化能升高37.17kJ/mol。     

1,3,5‐Trinitroperhydro‐1,3,5‐triazine (RDX)‐Based Sheet Explosive Formulation with a Hybrid Binder System

A plastic‐bonded explosive (PBX) in the form of a sheet was formulated comprising of 1,3,5‐trinitroperhydro‐1,3,5‐triazine (RDX) and an hybrid binder system containing a linear thermoplastic polyurethane and a fluoroelastomer (Viton). The effect of a fluoroelastomer on the explosive as well as mechanical properties and thermal behavior of sheet explosive formulations were investigated and compared with a control formulation containing 90 % of RDX and 10 % of natural rubber (ISNR‐5). The replacement of 10 % natural rubber by a hybrid binder system led to an increase in the velocity of detonation (VOD) of the order of 250–950 m s⁻¹ and better mechanical properties in terms of tensile strength (1.9–2.5 MPa) compared to the control formulation (RDX/ISNR‐5 (90/10)). The compatibility of ingredients and thermal decomposition kinetics of selected sheet explosive formulations were investigated by vacuum stability tests and differential scanning calorimetry (DSC). The results suggested better compatibility of RDX with the hybrid binder system (polyurethane/Viton), which is useful to reduce potential hazards in handling, processing, and storage.     

键合剂对RDX/HTPB推进剂界面粘结效能的影响

应用接触角测定仪测试了几种键合剂对ＲＤＸ／ＨＴＰＢ界面粘结效能的影响。选择了两种键合剂制备了ＲＤＸ／ＨＴＰＢ推进剂，测定了推进主 单轴拉伸力学性能和单拉伸破坏能。结果表明，键合改善ＲＤＸ／ＨＴＰＢ推进剂力学性能的主要原因在于它们改善了ＲＤＸ颗粒与ＨＴＰＢ粘结剂基体间的界面粘结效能。     

5‐Amino‐3,4‐dinitropyrazole as a Promising Energetic Material

The nitrogen‐rich energetic compound 5‐amino‐3,4‐dinitropyrazole (5‐ADP) was investigated using complementary experimental techniques. X‐ray diffraction indicates the strong intermolecular hydrogen bonding in 5‐ADP crystals. Compound exhibits low impact sensitivity (23 J) and insensitivity to friction. The activation energy of thermolysis determined to be 230±5 kJ mol⁻¹ from DSC measurements. Accelerating rate calorimetry indicates the lower thermal stability (173 °C) of 5‐ADP than that of RDX, which is probably the main concern about using this compound. 5‐ADP also exhibits good compatibility with common energetic materials (viz. TNT, RDX, ammonium perchlorate), including an active binder. The burning rate of 5‐ADP monopropellant is higher than that of benchmark HMX, while the pressure exponent 0.51±0.04 is surprisingly low. Addition of ammonium perchlorate does not affect the pressure exponent of 5‐ADP, while the burning rate increases. The 5‐amino‐3,4‐dinitropyrazole exhibits a notable combination of combustion performance, low sensitivity, and good compatibility, which renders it as a promising energetic material.     

改善高能硝胺发射药力学性能研究

为满足高膛压火炮对高能发射药力学性能的应用要求,优化了RGD7高能硝胺发射药基础配方的黏结剂体系,分析了高能固体填料RDX和NQ与黏结剂体系的界面粘结性能.用配方体系中加入键合剂方法改善了高能硝胺发射药的力学性能.     

改性水性聚氨酯乳液包覆RDX的合成研究

以聚四氢呋喃二醇(PTMG)为聚醚软段、甲苯二异氰酸酯(TDI)为硬段、DMPA(二羟甲基丙酸)为亲水扩链剂、环氧树脂(EP)和硅烷偶联剂为交联扩链改性剂,制取耐水性好、粘接强度高的改性水性聚氨酯(WPU)乳液;并以此作为黑索今(RDX)的包覆剂。结果表明:当w(EP)=6%(相对于物质总质量而言)、w(硅烷偶联剂)=2.0%(相对于物质总质量而言)和w(WPU)=2%(相对于RDX质量而言)时,经改性WPU乳液包覆后的RDX,其成型性、流散性和包覆效果较好,撞击感度和热感度明显降低。     

钝感剂对RDX热分解性能的影响研究

采用DSC对原料RDX和钝感剂与RDX的复合物进行了热分析测试,对样品的热分解动力学和热力学参数进行了计算和对比。结果表明,加入钝感剂(石墨或复合蜡)后,RDX在不同升温速率(2、5、10、20 K/min)下的放热峰峰温都得到了升高,热稳定性也有所提高,热力学参数发生明显的变化。     

Study on the Synthesis and Interfacial Interaction Performance of Novel Dodecylamine‐Based Bonding Agents Used for Composite Solid Propellants

An effective pathway was explored to design and select proper bonding agents that could effectively improve the interfacial interactions between bonding agents and solid particles, with three novel synthesized alkyl bonding agents, dodecylamine‐N,N‐di‐2‐hydroxypropyl‐acetate (DIHPA), dodecylamine‐N,N‐di‐2‐hydroxypropyl‐hydroxy‐acetate (DIHPHA) and dodecylamine‐N,N‐di‐2‐hydroxypropyl‐cyano‐acetate (DIHPCA), as examples. Molecular dynamics simulation was applied to compare unit bond energies of these bonding agents with the [110] crystal face of ammonium perchlorate (AP) and the [120] crystal face of hexogen (RDX). The infrared test was used to characterize the interfacial interactions of these bonding agents with AP or RDX. XPS test was applied to calculate the adhesion percentage of the bonding agents on the surface of precoated AP or RDX particles. All of the above results indicated that these three bonding agents have strong interfacial interactions with AP or RDX in the order of DIHPCA>DIHPHA>DIHPA. The prepared three bonding agents were used in HTPB/AP/RDX/Al propellants, and their effects on tensile strength (σ), elongation under maximum tensile strength (ε_m), elongation at breaking point of the propellant (ε_b) and adhesion index (Φ) of the propellant were studied. The results show that the bonding agents improve the mechanical properties of the propellant in the order of DIHPCA>DIHPHA>DIHPA. The methods found from theoretical design, materials synthesis, and mechanistics studies up to practical application show effective guiding significance for choosing the proper bonding agent and improving the interfacial interactions between the solid particles and binder matrix.