GAP基含能热塑性弹性体制备及其在复合固体推进剂中的应用进展

介绍了含能热塑性弹性体(ETPE)的概念及制备方法,分析了复合固体推进剂用ETPE的特点,综述了GAP(聚叠氮缩水甘油醚)基含能热塑性弹性体及GAP基热塑性推进剂的研究进展,针对GAP基ETPE在热塑性推进剂应用中存在的问题,提出了可能的解决方法,认为GAP基ETPE作为黏合剂将会是热塑性推进剂的一个发展方向。     

BAMO-GAP基ETPE的合成与性能研究

以3,3′-二叠氮甲基氧丁环均聚物(PBAMO)和4,4′-二苯基甲烷二异氰酸酯(MDI)为硬段,聚叠氮缩水甘油醚(GAP)为软段,1,4-丁二醇(BDO)为扩链剂,采用预聚体法合成了BAMO-GAP基含能热塑性弹性体(ETPE);采用FT-IR、NMR方法对ETPE的结构进行了表征;研究了合成条件对ETPE的力学性能、相对分子质量、玻璃化转变温度以及软化点的影响。结果表明,合成的ETPE符合预期结构;异氰酸酯指数(R)大于1时生成交联体。n(PBAMO)∶n(GAP)为0.35∶0.65时,ETPE胶片的力学性能最佳;随着n(PBAMO+GAP)∶n(MDI)∶n(BDO)中BDO比例的增大,ETPE的相对分子质量得到提高,改善了胶片的力学性能,PBAMO相对含量的提高导致玻璃化转变温度升高;软化点随n(PBAMO+GAP)∶n(MDI)∶n(BDO)中BDO所占比例、R值、n(PBAMO)∶n(GAP)的增大而升高。     

GAP基含能热塑性弹性体的合成与表征

以聚叠氮缩水甘油醚(GAP)为软段,1,4-丁二醇(BDO)和4,4′-二苯基甲烷二异氰酸酯(MDI)为硬段,采用熔融预聚体法合成了GAP基含能热塑性弹性体(ETPE)。研究了扩链剂加料方式、催化剂用量、异氰酸酯指数、硬段含量等因素对弹性体力学性能的影响。采用傅里叶变换红外光谱(FT-IR)、凝胶渗透色谱(GPC)、热台显微镜、差示扫描量热(DSC)、热重分析(TG)表征了ETPE的性能。结果表明,采用恒速滴加扩链剂方法合成的ETPE具有良好的热稳定性和力学性能。当催化剂质量分数为0.6‰,异氰酸酯指数(R)为0.98,硬段质量分数(Y)为35%时,热塑性弹性体的数均相对分子质量为52 312,软化点为96℃,拉伸强度为14.52MPa,断裂伸长率为518.78%。     

热塑性弹性体黏合剂在固体推进剂中的应用研究进展

介绍了热塑性弹性体(TPE)作为固体推进剂用黏合剂的特点、分类[如不含能热塑性弹性体、含能热塑性弹性体(ETPE)]和应用,重点综述了ETPE中聚叠氮缩水甘油醚(GAP)基和3,3-双(叠氮甲基)氧杂环丁烷(BAMO)基ETPE在推进剂中的研究进展。最后展望了TPE作为固体推进剂用黏合剂的发展前景。     

具有双软段的GAP基热塑性弹性体的合成与表征

采用熔融二步法,以聚叠氮缩水甘油醚(GAP)和聚醚酯为软段,以4,4’–二环己基甲烷基二异氰酸酯(HMDI)为固化剂,以1,4–丁二醇(BDO)、一缩二乙二醇(DEG)为扩链剂,制备具有双软段的含能热塑性弹性体(ETPE),通过傅里叶变换红外光谱仪、差示扫描量热仪、热重分析仪、静态热机械分析仪及电子万能试验机对该弹性体进行了结构和性能表征。结果表明,所制备的ETPE具有GAP含能弹性体的特征,聚醚酯的引入使弹性体的玻璃化转变温度(T_g)降低,T_g为–40.1℃,初始热分解温度为226.1℃(质量损失5%时的温度),弹性体具有良好的热稳定性,ETPE的常温拉伸强度为2.6 MPa,拉伸强度有明显的提高,断裂伸长率可达1 280%,满足热塑性推进剂对黏合剂技术指标要求。     

GAP型含能热塑性弹性体的合成及研究进展

概述了含能热塑性弹性体（ETPE）的概念、发展及优势,综述了近年来聚叠氮缩水甘油醚（GAP）型ETPE的合成和研究进展,分析了目前存在的问题和不足,并展望了GAP型ETPE的未来发展趋势及应用前景。     

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.     

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。     

含能黏合剂合成研究新进展

从热塑性含能黏合剂和热固性含能黏合剂两方面综述了国内外含能黏合剂近5年研究的最新进展,重点介绍了叠氮类、硝酸酯类、富氮含能类、聚磷氮烯类、改性端羟基聚丁二烯类热塑性含能黏合剂,GAP基ETPE、BAMO基ETPE、偕二硝基类热塑性含能黏合剂的合成及性能研究情况,对含能黏合剂研究的发展趋势进行了展望,附参考文献25篇.     

RDX/GAP纳米复合含能材料的制备及热性能

以聚叠氮缩水甘油醚(GAP)和六亚甲基二异氰酸酯(HDI)为原料,二月桂酸二丁基锡(T-12)为催化剂,通过溶胶-凝胶法及溶液结晶法制备了RDX/GAP纳米复合含能材料。用BET法、X-射线粉末衍射、扫描电镜对其结构进行了表征,用TG/DSC分析了其热性能。结果表明,RDX/GAP纳米复合含能材料具有纳米网孔结构,与GAP干凝胶相比,其比表面积下降,平均粒径为20~50nm。RDX/GAP纳米复合含能材料中的RDX热分解峰温明显提前,分解热显著高于RDX/GAP物理共混物的分解热。     

Synthesis and Characterization of 3,3′‐Bisazidomethyl Oxetane‐3‐Azidomethyl‐3′‐Methyl Oxetane Alternative Block Energetic Thermoplastic Elastomer

3,3′‐Bisazidomethyl oxetane‐3‐azidomethyl‐3′‐methyl oxetane (BAMO‐AMMO) tri‐block copolymer was successfully synthesized by azidation of a polymeric substrate containing bromo leaving groups, and an alternative block energetic thermoplastic elastomer (ETPE) was prepared by chain extension reaction. The tri‐block copolymer was characterized by Fourier transform infrared (FTIR), ¹H NMR, and ¹³C NMR spectroscopy, X‐ray diffraction (XRD), and thermogravimetric analysis (TGA). It was found that the composition of the copolymer is nearly 1 : 1; crystallinity of the copolymer (71.81 %) is less than that of PBAMO (78.30 %). This is due to a partly mixture between soft and hard segments. Kinetic result shows that a crosslinking network is formed after the decomposition of azide group. Tensile strength of alternative block ETPE is 150 % of traditionally synthesized BAMO‐AMMO ETPE.     

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     

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.     

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。     

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.     

Characterization of P(BAMO/AMMO) ETPE Prepared Using Different Diisocyanates

Poly(3,3‐bisazidomethyl oxetane/3‐azidomethyl‐3‐methyl oxetane) energetic thermoplastic elastomers (P(BAMO/AMMO) ETPEs) is one of the most valuable ETPEs in the field of energetic binders. P(BAMO/AMMO) ETPEs were prepared using different diisocyanates (TDI, HMDI, IPDI, and HDI) to investigate the influence of the diisocyanate on the performance of P(BAMO/AMMO) ETPEs. Mechanical properties and heats of formation were investigated. FT‐IR spectroscopy results showed that TDI‐based ETPE has the highest degree of hydrogen bonding with a value of 69.00 %. Mechanical test results showed that the TDI‐based ETPE has better mechanical property with maximum stress at 5.24 MPa and breaking elongation at 390 %. The order for degree of hydrogen bonding and mechanical property of different diisocyanate‐based ETPEs was TDI>HMDI>IPDI>HDI. The heats of formation were calculated by the group additivity method and by the heat of combustion method. The values of heats of formation for TDI‐based ETPE were 3.44 kJ g⁻¹ and 3.75 kJ g⁻¹ according to the two methods. Additionally, TDI‐based ETPE has a lager heat of formation than the other ETPEs.     

Multivariate Calibration of Semi‐Synthetic Data Sets: Gun Powder Analysis

Quantitative analysis of multi‐component mixtures such as propellant powders is not trivial since it usually requires separation of the mixture constituents. Multivariate calibration combined to the use of semi‐synthetic data sets can eliminate the need for standard solutions preparation, and therefore allow the rapid determination of mixtures provided no intermolecular interactions occur in the systems. Multivariate compositional analyses of FTIR spectra of low‐vulnerability (LOVA), high‐energy low‐vulnerability (HELOVA) and energetic thermoplastic elastomer (ETPE) propellant powder systems were performed using the partial least‐squares (PLS) regression algorithm. All constituents except ethyl centralite (EC) were quantified. Concentrations were predicted within 1% error for the major component (1,3,5‐trinitro‐1,3,5‐triazacyclohexane or RDX), and within 5% error for the minor components (between 12 and 2% nominally by weight). LOVA, HELOVA, and ETPE gun powder samples concentrations were estimated and compared to expected compositions.     

ETPE发射药表观黏度的实验研究

利用ARES应变流变仪测试了不同ETPE发射药配方的表观黏度,并对实验结果进行了数学处理,得到ETPE发射药不同配方的表观黏度与剪切应力关系式.结果表明,影响ETPE发射药表观黏度的主要因素是热塑性弹性体ETPE的相对分子质量、固体添加剂RDX的质量分数及其表面特性以及实验温度.用惰性材料处理RDX表面是调节ETPE发...     

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.