不同温度条件下HTPB推进剂干燥恢复研究

以在30℃、RH为100%条件下湿老化5 d的丁羟(HTPB)推进剂试样为研究对象,分别进行了在10、30、50℃3种温度下的干燥恢复试验,测试了干燥恢复过程中推进剂试样的失水率和力学性能。综合分析了试验数据,得到了不同温度下干燥时初始阶段推进剂试样的失水率、抗拉强度恢复速率,以及各力学性能参量恢复度90%且伸长率比值1.2的恢复时间。对抗拉强度测试中得到的断面照片进行了对比和分析,将样品30℃干燥恢复1、4、9 d后的单向拉伸曲线绘制在一张图上进行比较寻找规律,在对试验数据和试验现象分析总结的基础上探讨了HTPB推进剂干燥恢复过程中氢键的作用规律。     

光伏组件封装EVA的热空气老化研究

对光伏组件封装EVA胶膜进行了热空气老化研究。将EVA胶膜置于不同温度下进行热空气老化,测试了老化过程中EVA的抗拉强度、透光率和黄度指数,采用FT-IR、GPC、DSC技术对老化后的EVA进行分析。结果表明,随着老化的进行,EVA的抗拉强度快速下降,老化温度越高,抗拉强度下降越快,甚至完全失效,失去弹性;老化过程中EVA会变黄,透光率逐渐下降;老化失效原因主要是发生氧化降解,EVA的交联网状结构破坏,进而失去力学性能。     

丁羟推进剂的热加速老化力学性能及寿命预估

用单轴拉伸试验和扯离试验测试了不同老化温度(55、65、75和85℃)下热加速老化后丁羟(HTPB)推进剂的力学性能及其粘接试件的扯离强度,用Berthlot方程预估了推进剂及其粘接试件的寿命。结果表明,HTPB推进剂的最大延伸率随老化时间的增加呈现降低趋势;老化温度越高,推进剂的最大延伸率降低幅度越大,85℃贮存30d时最大延伸率降幅为29.81%,而55℃贮存30d时最大延伸率降幅仅为4.34%;粘接试件的扯离强度随着老化时间的增加呈降低趋势,老化时间相同时,扯离强度随老化温度的升高而降低。预估HTPB推进剂和推进剂粘接试件的贮存寿命分别为9.4y和15.9y。     

特种丁羟工艺助剂的使用性能

用锥板黏度计和落球黏度计监测HTPB推进剂组分的黏度及实时固化剂TDI的消耗速度,研究了特种丁羟工艺助剂HG的组成、含量对丁羟复合固体推进剂药浆的流动性、黏度增长速度、固化特性等的影响。实验结果表明,HG能显著改进含高阻湿键合剂等丁羟预聚体配方的工艺性能,而叉保持优良的固化特性和力学性能。TDI固化剂消耗速度的监测初步证明,这些改进作用由HG干扰固化反应或所谓的类固化反应所致。     

某高燃速丁羟推进剂配方研究

对高燃速、力学性能优良的丁羟推进剂进行了配方研究。该配方采用了HT-PB（端羟基聚丁二烯）、TDI（甲苯二异氰酸酯）粘合剂体系,选用101/102/103/106助剂以改善工艺性能和力学性能,通过优化AP工艺方法,使该丁羟推进剂具有固体含量为86%、密度≥1.78g/cm3、在50℃抗拉强度≥0.5MPa基础上,20℃...     

湿热环境对RDX/AP-NEPE推进剂热安全性及力学性能的影响

用TG、5s爆发点和单向拉伸试验,研究了湿热环境对RDX/AP-NEPE推进剂热安全性和力学性能的影响。结果表明,在相对湿度70%、温度75℃下经历6d的湿热老化后,RDX/AP-NEPE推进剂在TG曲线上的3个质量损失阶段的表观活化能均略有降低,水分对AP分解活化能的影响较为明显,使其活化能降低9.3%。湿热老化前后,5s爆发点Tb分别为303.7℃和302.7℃。随着老化时间的增加,延伸率和抗拉强度都呈降低趋势,至第6d延伸率从106.0%降至36.7%,抗拉强度从0.631MPa降至0.541MPa。在75℃下干燥热老化6d后,RDX/AP-NEPE推进剂3个阶段的表观活化能、5s爆发点、抗拉强度和延伸率都没有明显的变化。初期老化过程中,水分对RDX/AP-NEPE推进剂的力学性能和AP的分解活化能影响较大,但对热感度基本没有影响。     

Ⅰ类AP初始缺陷对丁羟推进剂力学性能的影响

分别以两种Ⅰ类高氯酸铵(AP)为氧化剂,采用立式混合及真空喷淋浇注工艺制备了两种丁羟推进剂(HTPB);采用扫描电镜(SEM)研究了AP的微观形貌及HTPB推进剂的拉伸断面;探讨了推进剂在拉伸过程中的破坏机理;考察了不同形貌的AP在常温(20℃)和低温(-40℃)下对HTPB推进剂单向拉伸力学性能的影响。结果表明,有初始微观形貌缺陷的Ⅰ类AP局部有微裂纹或明显的突出点,且该类AP所制备的推进剂"脱湿"现象严重;拉伸断面出现AP的穿晶断裂现象,使得推进剂在常温(20℃)下的抗拉强度由0.99MPa降至0.88MPa,延伸率由48.2%降至36.6%;低温(-40℃)下的抗拉强度由2.86MPa降至2.32MPa,延伸率由62.5%降至23.5%。     

Al粉对推进剂力学性能的影响

通过调整配方中Al粉的粒度及含量,来研究其对推进剂力学性能的影响。试验结果表明：球形Al粉粒度越小,推进剂的高温抗拉强度和低温延伸率越大;加入4#球形Al粉的推进剂的高温延伸率、低温抗拉强度和低温延伸率最大,综合力学性能较好;推进剂的抗拉强度和延伸率与其中的Al粉含量为非线性关系,Al粉含量对推进剂延伸率的影响较小;4种Al粉含量的推进剂中,Al粉质量分数为5.5%的推进剂的力学性能较好,可根据相关技术要求选择合适的配比进行推进剂的试制。     

基于HTPB改性多功能助剂的合成及性能分析

在多羟基、多胺基聚丁二烯(AEHTPB)的基础上,向其分子结构中引入硼酸酯基团,制备出多硼酸酯基、多胺基聚丁二烯(AEHTPB-B);通过红外光谱、核磁共振氢谱对产物的结构进行表征,并对产物的黏度、玻璃化温度、羟值、胺值等理化性质进行了分析;研究了AEHTPB-B对黏合剂基体力学性能的影响,并通过装药实验探究了AEHTPB-B对丁羟四组元推进剂力学性能及燃烧性能的影响,分析了AEHTPB-B对不同填料的键合效果。结果表明,AEHTPB-B可提高黏合剂基体强度,还可同时对高氯酸铵(AP)及黑索金(RDX)填料起键合作用,有效改善丁羟四组元推进剂的力学性能;当AEHTPB-B质量分数为8%时,常温下推进剂拉伸强度(σ_m)可提升29.2%,最大伸长率(ε_m)可提升63.3%,推进剂燃速降低11.7%。     

湿热条件下复合固体推进剂老化特性研究

为研究HTPB(端羟基聚丁二烯)、NEPE(硝酸酯增塑聚醚)2种复合固体推进剂在湿热贮存环境中的老化机理,开展了77%相对湿度、60℃和77%相对湿度、20℃条件下的贮存老化试验,实时监测了推进剂最大抗拉强度、冲击感度、邵氏硬度、热老化过程中质量的变化规律。研究发现:2种推进剂在湿热贮存环境下,最大抗拉强度随老化时间的延长持续下降;黏合剂分解是造成2种推进剂硬度变化的主要因素,且HTPB推进剂内部黏合剂受影响更大;NEPE推进剂冲击感度随老化时间增加逐渐降低,而HTPB推进剂则存在感度值回升现象;2种推进剂在湿热环境中质量均增大,且HTPB推进剂吸湿性更强。     

湿度对HTPB复合推进剂力学性能的影响

通过常温湿度试验,研究了HTPB复合推进剂力学性能随试验时间的变化规律.试验证明,湿度使HTPB推进剂的力学性能大幅度下降;经干燥后,其力学性能能够得到部分恢复.用扫描电镜对常温湿度试验前后推进剂的表面状态和拉伸断口进行了对比分析,结果表明,试验后推进剂表面的AP粒子形状有明显改变,拉伸断口上的AP粒子裸露面增大,粒子脱落坑表面光滑、规整.由此得出HTPB推进剂吸湿后,通过干燥方法不能使其力学性能恢复到原始状态.     

HTPB推进剂贮存试验研究与机理分析

以端羟基聚丁二烯（HTPB）推进剂为研究对象,进行了采取密封措施的高温加速老化试验、模拟热带海域高温高湿环境条件的贮存试验、干燥处理试验、密封环境压力对贮存效果的影响试验,并对其力学性能变化机理进行了分析和讨论。     

Development of Composite Solid Propellant Based on Nitro Functionalized Hydroxyl‐Terminated Polybutadiene

This paper presents an overview of a modified composite propellant formulation to meet future requirements. The composite propellant mixtures were prepared using nitro functionalized Hydroxyl‐Terminated Polybutadiene (Nitro‐HTPB) as a novel energetic binder and addition of energetic plasticizer. The new propellant formulation was characterized and tested. It was found that the Nitro‐HTPB propellant with and without energetic plasticizer exhibited high solid loading, high density, and reasonable mechanical properties over a wide range of temperatures. It was shown that the burning rate of Nitro‐HTPB propellant is up to 40% faster than that of the HTPB propellant. These results are encouraging and suggest that it should be possible to improve the ballistic performance of popular HTPB propellants through use of the studied Nitro‐HTPB binder.     

湿度对丁羟推进剂及其粘接性能的影响研究

固体火箭发动机燃烧室内绝热层、人工脱黏层及推进剂药柱,均为高分子材料复合体系。在成型及贮存过程中,湿度是影响丁羟推进剂药柱性能及各界面的联合粘接强度的首要因素。探讨了绝热层、衬层及推进剂药柱在不同环境湿度下的吸湿特性,通过模拟实际生产过程的环境湿度,研究了丁羟推进剂药柱性能及各界面的联合粘接强度变化状况。     

溶胀/溶解法回收HTPB推进剂中AP组分的实验研究

采用溶胀/溶解法回收报废HTPB推进剂中的AP。研究了浸取时间、浸取温度、四氢呋喃质量分数、液料比(四氢呋喃溶液体积与HTPB推进剂的质量比)、试样厚度及搅拌速率对AP回收率的影响。通过扫描电镜、X射线能谱仪对回收得到的AP进行表征,并对其纯度进行了检测。结果表明,AP的最佳回收工艺参数为:浸取时间6h、浸取温度60℃、四氢呋喃质量分数80%、液料比10∶1(mL/g)、试样厚度3mm、搅拌速率500r/min。其中,浸取时间、浸取温度和四氢呋喃质量分数对AP回收率的影响较大。在最佳工艺条件下,AP的回收率为95.0%,纯度为96.1%,表明此方法可用于报废HTPB推进剂中AP组分的回收。     

From Cross‐linking to Plasticization – Characterization of Glycerin/HTPB Blends

Usually, a plasticizer is a relatively low‐viscosity liquid ingredient that is added to improve the mechanical properties and the processing properties of a propellant, such as a lower viscosity for casting or a longer pot life of the mixed, but uncured propellant. The effects of many plasticizers on the performance of the composite propellant have been studied in detail. Glycerin is a triol, a low viscosity material, and inexpensive. It seems that the processing properties and the mechanical properties of the HTPB binder would be improved by the addition of glycerin. The curing behavior, the mechanical properties, and the thermal decomposition of a glycerin/HTPB blend have been investigated in this study. The viscosity of the glycerin/HTPB blend and the increasing ratio of the viscosity versus the elapsed time are lower than those of only HTPB. The mechanical properties are improved by the addition of glycerin, even for a low quantity of glycerin. The thermal decomposition behavior of the blend occurs at lower temperatures when compared to that of HTPB.     

An Investigation of Composite Propellant Accelerated Ageing Mechanisms and Kinetics

The ageing kinetics and mechanisms of a composite solid rocket propellant were investigated by monitoring unstressed propellant samples during prolonged storage at elevated temperatures. For samples confined under air during ageing, it was determined that oxidative cross‐linking of the propellant binder was the main degradation mechanism over time. Plasticizer loss was a significant ageing mechanism only for those samples aged unconfined. In addition, there was an indication that ambient humidity had a significant but reversible effect on propellant mechanical properties. Arrhenius mathematical relationships were derived in order to ascertain the extent to which ageing was accelerated by increased propellant temperature. An activation energy for binder oxidation of between 71 and 74 kJ/mol was determined.     

B/Fe_2O_3/NC复合物的制备及其对HTPB/AP推进剂性能的影响

为改善硼粉(B)的性能和纳米氧化铁(Fe_2O_3)在固体推进剂中的分散性,用静电喷雾法制备了B/Fe_2O_3/NC复合物,采用扫描电镜(SEM)表征了复合物的表面形貌,用TG-DSC分析了复合物的热性能及其对HTPB/AP推进剂热性能的影响,并用燃速测试和密闭爆发器实验研究了该复合物对HTPB/AP推进剂燃烧性能的影响。结果表明,所制备的B/Fe_2O_3/NC复合物均以团聚体的形式存在,复合物中B的活性提高,其氧化反应温度提前;团聚硼粉对HTPB/AP推进剂燃烧性能的改善效果明显优于原料硼粉;加入Fe_2O_3后,会进一步改善含硼推进剂的燃烧性能,而且随Fe_2O_3含量的增加,在密闭爆发器中HTPB/AP推进剂达到最高压力所需的时间逐渐减小。当Fe_2O_3的质量分数为8%时,推进剂在常压空气中的燃速最大,为不添加B/Fe_2O_3/NC复合物的HTPB/AP推进剂的2.77倍。B/Fe_2O_3/NC复合物对推进剂的热分解具有一定催化作用,且随Fe_2O_3含量的增加催化作用增强。     

Synthesis of GAP-PB-GAP Triblock Copolymer and Application as Modifier in AP/HTPB Composite Propellant

A new triblock copolymer polyglycidylazide-block-polybutadiene-block-polyglycidylazide (GAP-PB-GAP) has been synthesized. The synthesis was done by cationic ring opening polymerization of epichlorohydrin (ECH) with HTPB as the alcohol and boron trifluoride etherate as the catalyst followed by the conversion of the -CH₂Cl group into -CH₂N₃ group. The presence of the azido groups in the GAP polymer chain makes it more energetic and the triblock copolymer can be used as an energetic binder/additive for propellant energy modification. Since the triblock copolymer has polybutadiene (PB) as the central block, which is from HTPB itself, it can be used as an additive in HTPB based polymeric formulations to improve their properties. In the present work, a part of HTPB, the propellant binder in ammonium perchlorate (AP)/HTPB propellant was removed and replaced with the GAP-PB-GAP copolymer. Burn rate, mechanical properties, and heat of combustion properties of these propellants were measured and compared with the unmodified HTPB/AP propellant. The results show that the burn rate of the HTPB/AP solid propellant could be enhanced by the addition of the triblock copolymer.