Hu Yiwen, Song Xiuduo, Yang Weilu, Kang Jian
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China.
State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065, China.
Materials (Basel). 2024 Dec 24;18(1):19. doi: 10.3390/ma18010019.
The azido propellant, with high energy and low signature, has been a hotpot in the field of propellants. However, the risk of low heat resistance and mechanical performance restricts their range of applications in high-energy formulations. In this study, four azido propellants based on 3,3-bis (azidomethyl) oxetane-tetrahydrofuran copolyether (BAMO-THF) have been prepared, their basic physical properties including energetic properties, internal micro-structure and true density were studied; their tensile properties, dynamic mechanical performances, were investigated, the structure-properties relationship was proposed. The results demonstrate that the obtained propellant shows an elastomeric composite material behavior, with an obvious relaxation in the initial stage and susceptibility to loading condition. The formula structure not only causes obvious difference in the second stage of relaxation, but also strongly affects the initial stage, which is quite different from the influence of testing condition. Besides, the low temperature toughness of the azido propellant is improved by using diol partly replaces diamine as a chain extender, but their stress modulus drop down obviously, leading to the notable stress relaxation behavior at high temperatures. It was found that the improvement of the ordering degree of microstructure or network integrity could restrict the stress relaxation, which was an effective approach to improve the heat resistance and mechanical performance of azido propellant at high temperatures.
叠氮推进剂具有高能量和低特征信号，一直是推进剂领域的研究热点。然而，其耐热性和机械性能较差的风险限制了它们在高能配方中的应用范围。本研究制备了四种基于3,3-双（叠氮甲基）氧杂环丁烷-四氢呋喃共聚醚（BAMO-THF）的叠氮推进剂，研究了它们的基本物理性能，包括能量性能、内部微观结构和真实密度；研究了它们的拉伸性能、动态力学性能，并提出了结构-性能关系。结果表明，所制备的推进剂表现出弹性体复合材料的行为，在初始阶段有明显的松弛现象，且对加载条件敏感。配方结构不仅在松弛的第二阶段引起明显差异，而且对初始阶段也有强烈影响，这与测试条件的影响有很大不同。此外，通过使用二醇部分替代二胺作为扩链剂提高了叠氮推进剂的低温韧性，但它们的应力模量明显下降，导致在高温下有明显的应力松弛行为。研究发现，提高微观结构的有序度或网络完整性可以限制应力松弛，这是提高叠氮推进剂高温耐热性和机械性能的有效途径。
