硝胺类高能炸药微/纳分级结构的构筑与性能研究

The energetic materials with hierarchical micro/nanostructures not only have the advantage of nano-energetic materials, such as lower sensitivity, higher energy release rate and combustion efficiency, but also overcome the shortcomings of nano-energetic materials of easy aggregation, bad formability and compatibility et al. So, they have great potential in many fields. However, less investigation involves the high-energy ammonium nitrate explosives in the field of energetic materials with hierarchical micro/nanostructures presently. The important reason is the lack of system research of construction pattern and formation mechanism of hierarchical micro/nanostructures for this kind of explosives. This project takes the typical high-energy ammonium nitrate explosives of second- and third- generations, HMX and CL-20, as the research object. Through the reasonable design of liquid-liquid interface phase, the hierarchical micro/nanostructures of HMX and CL-20 are constructed by the liquid-liquid interface crystallization via the diffusion-limited effect. The formation mechanisms of the hierarchical micro/nanostructures are revealed by studying the effects of composition and morphology of interface phase as well as crystallizaiton conditions on nano-building blocks formation and their assemble pattern. The relationship of the basic performance parameters and structures is set up through the characterization of structure and the test of performance. The studied results of this project will achieve the regulation of hierarchical micro/nanostructures for the high-energy ammonium nitrate explosives, and provide the technology support for their application in high and new technology field of the national defense, such as, explosive logic network, miniature detonating device, and propellant et al. Moreover, this investigation will also enrich and develop the crystallization theory of high-energy ammonium nitrate explosives.

微/纳分级结构含能材料不仅具有纳米含能材料能量释放速率高、燃烧效率大、低敏感性等优点，且可克服纳米含能材料易团聚、加工成型性不良和兼容性差等缺点，因而具有突出的应用前景。但目前微/纳分级结构含能材料对硝胺类高能炸药涉及很少，其重要原因是缺乏对此类炸药微/纳分级结构构筑方式及形成机理的系统研究。本项目拟以第二代和第三代典型硝胺类高能炸药HMX和CL-20为研究对象，采用液-液界面结晶技术，通过设计合理的液-液界面相，在扩散受限条件下构筑其微/纳分级结构；研究界面相组成、形貌及结晶条件对纳米结构单元形成及其组装方式的影响，揭示微/纳分级结构的形成机理；通过结构表征和基本性能参数测试，建立构效关系。项目研究成果将实现硝胺类高能炸药微/纳分级结构的调节和控制，为其在爆炸逻辑网络、微型起爆器件和推进剂等国防高新技术领域的应用提供技术基础，并丰富和发展硝胺类高能炸药的结晶理论。

微/纳分级结构含能材料既具有纳米含能材料的优势，即能量释放速率快、燃烧效率高，在低敏感性方面具有潜在优越性，而且可克服纳米含能材料易团聚、加工成型性不良和流散性差等缺点，同时微/纳结构的耦合作用又将赋予含能材料新的性能，因此开展微/纳分级结构含能材料的研究，对提高含能材料存放和使用安全性、改善武器作战性能以及发展高新武器具有极其重要的意义。. 本项目开展了硝胺类高能炸药微/纳分级结构的构筑与性能研究，主要研究内容如下：（1）液-液界面结晶构筑HMX的微/纳分级结构：通过界面相的设计和结晶过程控制，液-液界面结晶得到了蒲公英状的HMX，由平均粒径为383.4 nm的颗粒构成。但由于样品中含有少量晶型，导致其摩擦和撞击感度均高于原料。通过对结晶过程的原位观察，基于界面化学和结晶学基本原理，得到蒲公英状HMX的形成机制，即主要受控于溶剂的扩散速率和基于界面浓度梯度的晶体生长速率；（2）溶剂/非溶剂构筑含CL-20和TATB的微/纳分级结构：利用强烈的非溶剂效应和温度效应，构造CL-20和TATB的过饱和度差异，得到了含CL-20和TATB的微/纳分级结构。其微米颗粒由-CL-20纳米片堆垛而成，片层间夹杂有纳米枝状TATB，堆垛结构表面进一步被纳米枝状TATB包覆，形成致密包覆层。该复合炸药具有多重降感效应，导致其撞击感度远远低于原料CL-20和相应的机械混合物，接近于钝感炸药LLM-105；（3）仿生法构筑含CL-20和AP的微/纳分级结构。以具有精细分级结构的碳化蝶翅（CWs）作模板，通过受限结晶将CL-20和AP负载到CWs三维骨架中，获得CWs/CL-20/AP纳米结构含能复合物。具有多通道、分级孔结构和3D分级周期结构的CWs /CL-20/AP，由于其优异的热传导性能和压力补偿效应，同时其超薄自支撑结构也有利于自蔓延燃烧和装药操作，因此可作为微型推进器中的高能量密度化学燃料，实现其小尺寸、高效率、自蔓延稳态燃烧，有效解决由于微型推进器装药尺寸小（接近或小于燃料的临界燃烧尺寸）、比表面和体积之比高而导致的燃烧不稳定和燃烧效率低等核心问题。