固体推进剂组分相容性的分子动力学模拟

运用分子动力学模拟(MD)研究了固体推进剂组分1,2,4-丁三醇三硝酸酯(BTTN)、硝化甘油(NG)、奥克托金(HMX)、端羟基聚丁二烯(HTPB)、葵二酸二辛脂(DOS)和二乙基二苯脲(EC)的性质及其相容性;在COMPASS力场下,模拟计算了上述化合物及其共混体系的结合能、内聚能密度、溶度参数和共混体系分子间的FloryHuggins相互作用参数;通过比较溶度参数差值(Δδ)、Flory-Huggins相互作用参数等预测了推进剂组分间的相容性;通过结合能分析,揭示混合物组分分子的相互作用本质。结果表明,BTTN、NG均与EC相容,HTPB与DOS是相容体系,而HTPB/NG、HMX/BTTN和HMX/NG体系均为不相容体系。     

原位聚合包覆HMX的研究

为探索制备PBX的新方法,利用原位聚合反应,直接在HMX表面包覆一层热塑性高聚物,获得了分别以端羟基聚丁二烯(HTPB),聚叠氮缩水甘油醚(GAP)、3,3-双(叠氮甲基)环氧丁烷-四氢呋喃共聚醚(BAMO-THF)3种黏结剂包覆的PBX.通过光学显微镜、显微-红外、光电子能谱(XPS)、元素分析和机械感度测定对包覆效果进行表征.结果表明,HMX表面较均匀地包覆上了一层聚合物,黏结剂的质量分数约为4%～5%,包覆HTPB的HMX机械感度明显下降,而包覆GAP和BAMO-THF的HMX机械感度略有降低.     

TNT与主炸药HMX及CL-20之间的结合能对比

以ε-CL-20和β-HMX为主体炸药,分别与TNT混合,运用分子动力学(MD)方法研究和计算两者之间的结合能。结果表明,TNT与CL-20炸药的结合能要比TNT与HMX之间的结合能大,也就是TNT与CL-20之间的相容性较好。     

浇注PBX药浆适用期的研究

对浇注PBX用HTPB—TDI黏结剂体系进行了研究。通过选择合适的催化剂二月桂酸二丁基锡（T-12）缩短HTPB—TDI黏结剂体系的固化周期;通过选择有效的抑制剂乙酰丙酮（HAA）与催化剂T-12联合使用延长HTPB—TDI黏结剂体系的适用期,并达到缩短浇注PBx固化周期的目的。通过测定HTPB—TDI黏结剂体系的黏度,评价了加入催化剂和抑制剂方式对浇注PBX黏结剂体系的适用期的影响,找出合适的T-12与HAA摩尔比为4：1。     

HMX/AP/Al/HTPB推进剂燃速模拟计算

考察了 HMX/AP/HTPB 推进剂及其组分的热分解特性,当混合氧化剂HMX 和 AP 之质量比为1:1时,其热分解曲线呈现出独特的单峰放热分解特征。考察了十种添加剂对 HMX、AP、HMX/AP 和 HMX/AP/HTPB 热分解性能影响以及对 HMX/AP/Al/HTPB 推进剂燃速的影响。提出了改进的 BDP 模型和燃速模拟计算。     

双(二羰基环戊二烯铁)对高氯酸铵热分解性能的影响

采用SEM(扫描电镜)、XPS(X射线光电子能谱)等表征了双(二羰基环戊二烯铁)(简称Fe1)的微观形貌和Fe元素的价态,采用摩擦感度、静电感度和冲击感度测试了Fe1与推进剂相关组分HTPB(端羟基聚丁二烯)、AP(高氯酸铵)、HMX(奥克托今)的安全性能,采用DSC-TG(差热–热重)研究了AP/Fe1及HTPB/Al/AP/HMX/Fe1推进剂的催化热分解性能。结果表明:Fe1的pH为5.79,密度为1.76g/cm~3,其中Fe为零价;Fe1与推进剂相关组分HTPB、AP、HMX的安全性能良好;Fe1催化AP的热分解,AP的转晶峰温提前了2℃,低温分解峰和高温分解峰分别提前了6℃和54℃;在HTPB/Al/AP/HMX推进剂中添加质量分数为5%的Fe1,AP的高温分解峰提前48.1℃;Fe1具有大幅提高HTPB推进剂燃速的潜力。     

HMX/AP/Al/HTPB推进剂燃速模拟计算

考察了HMX/AP/HTPB推进剂及其组分的热分解特性,当混合氧化剂HMX和AP之质量比为1∶1时,其热分解曲线呈现出独特的单峰放热分解特征.考察了十种添加剂对HMX、AP、HMX/AP和HMX/AP/HTPB热分解性能影响以及对HMX/AP/A1/HTPB推进剂燃速的影响.提出了改进的BDP模型和燃速模拟计算.     

丁三醇三硝酸酯与高分子黏合剂的相互作用

运用半经验分子轨道理论PM3方法计算丁三醇三硝酸酯(BTTN)分别与聚乙二醇(PEG)、端羟基聚丁二烯(HTPB)、缩水甘油叠氮基聚醚(GAP)、3-叠氮甲基-3-甲基环氧丁烷聚合物(AMMO)和3,3-双(叠氮甲基)环氧丁烷聚合物(BAMO)等高分子黏合剂所形成的混合体系模型物,求得稳定几何构型.由色散能校正电子相关,求得其结合能.计算结果表明,高分子黏合剂HTPB、AMMO与BTTN的结合能(绝对值)随着高分子聚合度的增加而增大,而BAMO、GAP、PEG与BTTN间的结合能呈不同规律.GAP、AMMO和BAMO与BTTN的结合能略大于HTPB和PEG.     

超细HMX的表面能研究

用DCAT21型表面/界面张力仪测量了原料HMX（奥克托今,45μm～62μm）、超细HMX（0.2μm～1.7μm）和黏结剂FPM2602的接触角,并计算出它们的表面能。分析了HMX随粒径变化时其表面能的变化规律和黏结剂包覆超细HMX表面能的基本要求。结果表明,细化HMX表面能随粒径的减小有增加的趋势;黏结剂的表面能低于超细HMX的表面能,理论和实验均证明黏结剂FPM2602能包覆于超细HMX的表面。     

端羟基聚丁二烯基聚氨酯的溶胀试验研究

以HTPB(端羟基聚丁二烯)基PU(聚氨酯)作为RDX(黑索金)/AP(高氯酸铵)含能材料包覆用黏合剂,在废弃复合推进剂的回收过程中,比较了7种溶剂对HTPB基PU溶胀效果的影响;采用红外光谱(FT-IR)法对RDX、AP在三氯甲烷中浸泡前后的结构进行了表征,并采用分子动力学模拟计算了溶剂与HTPB基PU的结合能、溶剂在其中的扩散系数。研究结果表明:三氯甲烷对HTPB基PU的溶胀率相对最高(700%),7种溶剂对HTPB基PU的溶胀率依次为三氯甲烷甲苯苯二氯甲烷环己烷乙酸乙酯丙酮;温度对溶胀率没有明显的影响,仅仅缩短了溶胀平衡所需的时间;浸泡前后RDX和AP的特征峰没有发生变化,说明两者与三氯甲烷未发生反应;分子动力学模拟计算而得的结合能、扩散系数判定的溶胀效果排序与溶胀率大小排序基本吻合。     

聚醚环酰胺类键合剂与HMX粘附性能的研究

采用扫描电镜（SEM）、傅里叶变换红外光谱（FT—IR）、X射线光电子能谱（XPS）差示扫描量热法（DSC）等分析技术对3种聚醚环酰胺键合剂包覆HMX晶体后的性能进行了表征。实验表明,聚醚环酰胺类键合剂不仅对HMX具有良好的粘附性能,而且与HMX有较好的相容性,从而证实聚醚环酰胺类作为HMX键合剂的有效性。     

Study of Thermal Reactivity and Kinetics of HMX and Its PBX by Different Methods

Vacuum Stability Test (VST) was used to determine the thermal behavior and kinetic parameters of 1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and its mixture with hydroxyl-terminated polybutadiene (HTPB) as a binder coded as HMX/HTPB.Model fitting and isoconversional method were applied to determine the kinetic parameters based on VST results.For comparison,non-isothermal thermogravimetry analysis data (TGA) was also used to calculate the kinetic parameters by using Kissinger,OFW (Ozawa,Flynn,and Wall) and KAS (Kissinger-Akahira-Sunose) methods.Advanced Kinetics and Technology Solution (AKTS) software was also used to determine the decomposition kinetics of the studied samples.Differential Scanning Calorimetry (DSC) was employed to determine the decomposition heat flow properties of the studied samples.Results show that the activation energies obtained using VST results is 360.1kJ/ mol for pure HMX and 186.9kJ /mol for HMX/HTPB.The activation energies obtained by the three different methods using TGA results are in the range of 360-368kJ/mol for pure HMX and 190-206kJ/mol for HMX/HTPB.It is concluded that values of kinetic parameters obtained by VST are close to that obtained by the different techniques using TG/DTG results.The onset decomposition peak of HMX/HTPB is lower than that of HMX where the HTPB binder has negative effect on the thermal stability of HMX.The results of all the applied techniques prove that HMX/HTPB has lower activation energy and heat release than the pure HMX.HTPB polymeric matrix has negative effect on the kinetic parameters of HMX.     

Laser‐Induced Deflagration of Unconfined HMX – The Effect of Energetic Binders

The effect of three energetic binders [poly(3‐methyl‐3‐nitratomethyloxetane (polyNIMMO), polyglycidyl nitrate (polyGLYN) and an energetic polyphosphazene (PPZ‐E) – all at 10%] on the unconfined laser‐induced deflagration of cyclotetramethylene tetranitramine, commonly known as High Melting point Explosive (HMX) by a near IR (NIR) diode laser (801 nm) has been examined. Hydroxyl terminated polybutadiene (HTPB) and PPZ (the precursor to PPZ‐E – before nitration) were used as reference materials. The formulations required the addition of an optical sensitizer – carbon black (CB) – for ignition. At the designated threshold flux density of 2.3 kW cm⁻², a minimum of ∼1 wt.‐% CB was needed for the reliable ignition of unbound HMX and its formulations with polyGLYN, PPZ‐E and PPZ. Under similar conditions HMX/polyNIMMO and HMX/HTPB required 3% CB. Ignition maps (ignition time versus laser flux density) have been constructed for the five formulations. Comparison of ignition times and ignition energy densities for HMX and HMX/polyGLYN showed this binder to have only a marginal effect. In contrast, HTPB, PPZ and PPZ‐E all retarded HMX ignition at the threshold flux density, but showed negligible effect at higher flux densities. As PPZ and PPZ‐E produced both similar delays in the ignition time and similar increases in the flame development times (10–90%) at the threshold flux density, the inhibition of the HMX ignition by these PPZs appears to be largely independent of the polymer energy content. Such characteristics could be useful for high performance and insensitive energetic formulations. PolyNIMMO (3% CB) increased the ignition time of HMX only slightly at 2.3 kW cm⁻². However, at this threshold flux level the HMX flame development times with polyNIMMO or HTPB were much longer than that for the unbound material; this effect is attributed to the enhanced CB content.     

叠氮推进剂的感度和能量特性研究

对叠氮推进剂的感度和能量特性进行了理论计算,得到了采用硝化甘油/低感度硝酸酯混合体系来降低冲击感度和摩擦感度的有效方法,以及高能量叠氮缩水甘油醚(GAP)推进剂各主要组分含量。增塑剂为硝化甘油/丁三醇三硝酸酯(NG/BTTN),增塑比为2.0,Al粉、高氯酸铵(AP)和奥克托今(HMX)质量分数分别为18%、30%和22%。     

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。     

星形PLA-HTPB聚氨酯共聚物的合成与表征

采用自制的星形聚乳酸(PLA)和端羟基聚丁二烯(HTPB)为主要原料,甲苯-2,4-二异氰酸酯为扩链剂合成了星形PLA-HTPB聚氨酯共聚物,通过FT-IR、DSC、TG等测试手段对此共聚物的结构与性能进行表征。结果表明,星形PLA-HTPB聚氨酯共聚物两相具有各自的玻璃化转变温度,两相之间存在相分离现象;其热分解过程为2步,乳酸链段的起始热分解温度为229℃,表观活化能为83.11kJ/mol,反应为一级反应;丁二烯链段的起始热分解温度为414℃,表观活化能为192.83kJ/mol,反应为非一级反应。     

AP/Al/SMX/HTPB四组元推进剂能量特性的理论研究

采用推进剂性能评估软件(PEP),计算和比较了2,3-二羟甲基-2,3-二硝基-1,4-丁二醇四硝酸酯(SMX)和HMX取代高氯酸铵/铝粉/丁羟黏合剂(AP/Al/HTPB)推进剂中AP对配方能量性能的影响。用高温化学平衡计算代码模拟计算了AP/Al/SMX/HTPB和AP/Al/HMX/HTPB复合固体推进剂的能量和标准发动机工作过程。结果表明,与HMX相比,SMX能在更大的配比范围内提高HTPB推进剂的能量水平。在质量分数14%HTPB、18%Al的配方中,SMX能有效将推进剂的平衡流比冲提高到2 622.5N·s/kg,比HTPB三组元能量优化配方高27.5N·s/kg。在质量分数14%HTPB、15%Al的配方中,SMX取代AP后,比冲最高可达2 634.2N·s/kg,比HTPB三组元能量优化配方高39.2N·s/kg。在质量分数15%Al、HTPB质量分数为12%和10%的配方中,SMX质量分数可分别达到45%和65%;最高比冲可分别达到2 652.9和2 679.3N·s/kg,比HTPB三组元能量优化配方分别高57.9和84.3N·s/kg。在不含Al或Al含量很低的配方中,SMX可取代全部AP。