PBX中多层次、多尺度导热网络的构筑及导热增强效应研究

Under the new situation, a high requirement of environmental adaptability for the explosive components has been put forward with the development of weapon tactical environment. The low thermal conductivity of PBX cannot meet the specific military needs. And enhancing the thermal conductivity of PBX is a key route to improve the environmental adaptability. At present, the structural defects of thermal conductive fillers and the thermal resistance between filler and polymer matrix are becoming a bottleneck for the effectively improving the thermal conductivity of composites. This problem has not been properly solved up to now. In this work, a kind of multi-level nanoscale high thermal conductive filler will be firstly prepared, which can overcome the defect of single filler and yield synergistic effect. Secondly, based on this high thermal conductive filler, the multi-level microscale thermal conductivity networks, which include different dimensions and layer space arrangement designs, will be further constructed in PBX. Consequently, the multi-level and multi-scale high efficiency thermal conductive networks can combine the advantages of structural designs of conductive fillers and conductive paths, and are expected to break through the bottleneck problem of thermal conductivity enhancement for composites and realize the effective promotion of thermal conductivity. Besides, by the performance characterization and theoretical calculation, the structure-activity relationship between the multi-level/scale structural design and the macroscopic thermal conductivity can be revealed, which will then provide theoretical basis for the thermal conductive structural design and building of PBX and have important theoretical significance and military application value.

新形势下，武器作战环境的发展对炸药部件的环境适应性提出了更高的要求，现有PBX 的导热系数偏低，无法满足特殊的军事需求，而增强PBX的导热系数是提升环境适应性的关键途径。目前导热填料本身结构缺陷及界面热阻是限制复合材料导热系数有效提升的核心瓶颈问题，至今未能得到有效解决。本项目拟首先制备一种多层次纳米尺度的高导热填料，克服单一填料的缺陷，组合优势和协同增强，其次，基于这种高导热填料进行多层次微观尺度导热网络构筑，包括不同维度和层空间排列设计，结合导热填料结构设计与导热通路设计的优势，最终在PBX中构筑一种多层次、多尺度的高效导热网络，突破复合材料导热提升的瓶颈难题，实现导热性能的有效提升。并辅以性能表征和理论计算，揭示多层次尺度结构设计与PBX宏观导热性能的构效关系，为PBX导热增强结构的设计和构筑提供理论依据，具有重要的理论意义和军事应用价值。

新形势下，各种复杂的作战环境和任务需要炸药部件具有良好的环境适应性，而现有的炸药晶体与粘结剂的导热系数偏低，不利于热量的传递，炸药部件内部会很容易产生温度梯度，导致材料热膨胀不均匀而产生热应力，影响和制约武器系统的可靠性和使用寿命。而提高PBX的导热系数是增强环境适应性的关键途径。目前，导热填料本身结构缺陷及界面热阻是限制复合材料导热系数有效提升的核心瓶颈问题，至今未能得到有效解决，同时传统的导热通路结构也并不能最大程度优化填料空间排列以实现填料间高效搭接和连通。针对上述问题，本项目首先对高导热石墨烯填料进行表面修饰和调控，修补结构缺陷和降低界面热阻，增强声子传输效率，进一步提升填料的导热增强效率。掌握了多尺度填料结构演变对PBX复合材料导热性能的影响机制。其次，基于导热填料，进行多层次的微观尺度的导热网络构筑，开发和掌握多种新型多层次微观尺度导热通路的构筑方法，搭建高效导热通路，获得导热网络设计对PBX导热性能影响的规律和机制。最后，通过多层次/尺度导热网络的构筑和调控，实现PBX复合材料导热性能的有效提升，仅0.5wt%用量下，对低导热HMX基PBX的热导率提升达89.5%，显著改善现有炸药的环境适应能力。结合理论计算与模拟，揭示了这种多层次/尺度结构设计与PBX宏观导热性能的构效关系。通过本项目的研究，为切实解决PBX复合材料的低导热特性提供了有益的创新思路、理念和关键技术，并为有效提升武器系统中炸药部件的环境适应性提供关键理论基础和技术储备，具有重要的军事应用前景。