富氮稠环吡(咪)唑并四嗪类高能低感炸药的设计、合成与性能研究

The contradictory relationship between high performance and low sensitivity is the main challenge in the development of high-energy explosives. Whereas energetic salts based on nitrogen-rich fused heterocycle show great advantages in coordinating the conflict, making them a potential class of high-energy explosives with low sensitivity and thermal stability. In the pursuit of high energy, nitrogen-rich backbones based on pyrazolotetrazine and imidazotetrazine were designed for enhancing densities of energetic precursors. Intense ring strain and lots of energetic C-N and N-N bonds in system result directly in high positive heats of formation. The introduction of energetic oxidation groups improves the oxygen balance, thus guaranteeing the excellent detonation performance of energetic salts. On the other hand, the favorable structural factor arose from highly delocalized negative charge throughout conjugated nitrogen-rich fused heterocycle anions supports stability toward heat and physical stimuli. Furthermore, hole buffering and strong interactions between anions and cations would greatly enhance the safty tendency. The research result would innovate the design strategies for high-energy and low- sensitivity explosives, also offer key theoretical and technical support for practical application of energetic salts based on nitrogen-rich fused heterocycle.

高能量水平和高稳定性的对立关系一直是高能炸药研究领域的挑战难题。而富氮稠环含能离子盐在协调高能量与高稳定性的矛盾方面具有巨大优势，是一类新型的应用前景广阔的高能低感单质炸药。本项目针对高能量要求，设计吡(咪)唑并四嗪的富氮稠环骨架，提高了含能母体密度；稠环张力与大量含能的C-N与N-N键提供了较高的正生成焓；引入的氧化性爆炸基团改善了体系的氧平衡，创造了离子盐产生高能量水平的内在条件。针对高稳定性要求，构建电子云高度离域化的富氮稠环阴离子；利用富氮阳离子与其相互作用以及“空穴”缓冲力，赋予离子盐高热稳定性与低感度。本项目创新了高能低感单质炸药的设计思想，为推进富氮稠环含能离子盐的实际应用提供了重要的理论与实验依据。

高能量水平和高稳定性的对立关系一直是高能炸药领域的挑战难题。而富氮稠环含能离子盐在协调高能量与高稳定性的矛盾方面具有巨大优势，是一类应用前景广阔的新型单质炸药。国内外已经有不少基于1,2,4-三唑的稠环含能材料的研究报道，[1,2,4]三唑[4,3-b][1,2,4]三唑是其中一种结构优异的稠环骨架。但是目前研究都是针对其含能阳离子；尚未有含能阴离子的报道。更重要的是，其阳离子含能材料的氧平衡OB很低。一般情况下，含能材料的OB越高，爆轰性能越高。.本项目设计并合成了全硝胺化的[1,2,4]三唑[4,3-b][1,2,4]三唑化合物(其阴离子OB = -2.8%)，并衍生出了6种含能盐。利用X-射线单晶衍射确证了胍类盐5•H2O，6•0.72H2O和7的单晶结构。利用13C NMR、1H NMR、IR和DSC等对该系列含能离子盐进行了全面表征。它们具有较好的热稳定性，分解温度介于151~235℃，密度介于1.65~1.89 g cm−3，氧平衡则介于−42.8%~−11.3%。利用Gaussian 09软件结合EXPLO5计算其爆速为8519~9518 m s˗1，爆压为27.6~41.1 GPa。撞击感度IS为4~8 J，摩擦感度为108~252 N。.具有高密度（d = 1.86 g cm−3）和不错的OB(-22.3％)的双铵盐2，其爆轰性能(vD = 9292 m s-1，P = 36.9 GPa）与感度(IS = 8 J, FS = 192 N)都明显高于于RDX。在该系列含能盐中，双羟胺盐3拥有最高的密度(d = 1.89 g cm−3)和最好的OB(-11.3％)，优于HMX的爆轰性能(vD = 9518 m s-1，P = 41.1 GPa)，但比HMX稍敏感(IS =5 J, FS = 108 N)。这些性能表明，2和3作为的高能密度材料的应用潜力较大。