Dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) is an energetic ion salt with high energy and low mechanical sensitivity. However, its poor morphology and low binding ability with conventional binders have significantly limited its application. In the present work, we reported a novel strategy to improve the morphology and surface properties of TKX-50 using sodium alginate (SA) as the modifier by the anti-solvent method. The results of imaging characterization indicated that SA greatly affected both crystal habit and morphology of TKX-50, resulting in modified TKX-50 granulars with low aspect ratios. The formation mechanism was explored by the molecular dynamics simulation. The XPS and SEM characterizations also revealed that SA adhered onto TKX-50 surface to form a coating layer. The non-isothermal kinetic parameters were calculated from DSC results. Our work has provided a new strategy to improve the morphology and surface properties of TKX-50 for its practical applications.
Yuanyuan Yao,Dongze Li,Shaohua Jin,Zifeng Wang,Dongxu Wang,Qinghai Shu
Strong corrosiveness to metals is the main factor restricting the widespread application of the insensitive explosive 3-nitro-1,2,4-triazole-5-one (NTO). Herein, MXene rich in active functional groups was obtained by selective etching of Ti3AlC2, and fine-grained MXene/NTO composites with rod-like morphology were prepared by recrystallization. The incorporation of MXene not only significantly reduced the particle size of explosives from 25 to 8 μm, but also weakened the impact sensitivity from 32% to 20% and friction sensitivity from 28% to 16%. Meanwhile, the enhanced corrosion resistance and thermal stability of the resulting NTO/MXene composites benefited from the introduction of MXene. The corrosiveness of NTO aqueous solution to metals was due to the easy ionization of hydrogen in the molecular structure, MXene with active groups combined with hydrogen atoms in NTO by non-covalent bonds, resulting in difficult hydrogen ionization and corrosion resistance without changing the chemical properties of explosives. The good thermal conductivity of MXene endowed NTO with improved thermal stability and promoted the crystallization of NTO as a nucleating agent. These insensitive explosives with good comprehensive properties would be the mainstay of the upgrading of weapons and equipment.
Energetic substances with layered crystal packing have been identified as the most promising next-generation high-energy materials (HEMs) due to their excellent insensitivity. The challenge, however, is how to design layered HEMs. In this study, a novel strategy called “acceptor–donor separation” was proposed to control the layer-by-layer stacking of energetic molecules through directional hydrogen boding: that is, a hydrogen bond donor and acceptor are located in different energetic segments and at least one of them has a conjugated planar structure, which will enable the energetic fragments to be infinitely extended in a two-dimensional plane to form a target layered structure. The experimental results showed that three exemplary substances designed by using this strategy possess the expected layered structures, which have been confirmed by single-crystal X-ray diffraction, demonstrating the robustness of this strategy. Moreover, the three as-synthesized HEMs all exhibit excellent insensitivity (impact sensitivity IS > 40 J; friction sensitivity FS > 360 N), affording safety far beyond those of the most powerful HEMs in use today. Especially, the hydroxylammonium energetic salts possess good detonation performance (detonation velocity D = 8924 m s–1; detonation pressure P = 36.9 GPa) comparable to that of 1,3,5-trinitro-1,3,5-triazine (RDX), one of the most powerful high explosives in use today.
危险品化学品经营许可证（带存储）