1. Layered assembling of energetic molecules with improved thermostability templated by in-situ generated 2D crosslinked macromolecules.
- Author
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Xue, Zhi-Hua, Zhang, Haorui, Wang, Zikangping, Xu, Ruixuan, Zhang, Yiran, and Yan, Qi-Long
- Subjects
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CROSSLINKED polymers , *MACROMOLECULES , *THERMAL stability , *ENERGY density , *MOLECULES - Abstract
Energetic materials play an irreplaceable role in both civial and millitary applications. The development of new energetic materials with high energy but low sensitivity has become the major challenge for this community. The diagram describes the interdependence of detonation properties, thermal stability and sensitivity of existing energetic materials, and it clearly shows that L-HMX is the target idea product of EMs that balances all the performances. [Display omitted] • The strategy of hybridization or so-called host/guest is completely new. A new method of in-situ crosslinking macromolecular 2D materials in an organic explosive solution was developed. Layered high explosive crystals L-HMX have been prepared, which are presented in a single layer with a thickness of 6 nm. • The hybrid crystals have unexpected layered structures with permanent configuration changes, resulting in higher packing density. L-HMX shows great fluorescence characteristics with a laser at wavelengths less than 1024 nm. • The hybrid energetic crystals show great balance in energy density and sensitivity. The calculated VoD value of L-HMX was higher than that of pure HMX. Meantime, the mechanical sensitivity of L-HMX crystals is significantly lower than that of pure HMX. Low-sensitivity but high-energy layered HMX crystals have been prepared by using an in-situ crosslinked network as the templated confinement, following a solvent-antisolvent procedure. The as received layered-HMX (L-HMX) crystals have only three diffraction peaks at 13.8°, 28.0° and 42.6°. It reveals that the conformation of the HMX molecule was largely changed after the squeezing and templating effect of the high nitrogen layers. The endothermic peak was not observed prior to decomposition, as the polymorphic transition and melting processes were excluded. This suggests that a new phase of HMX has been achieved. Unexpectedly, the L-HMX also shows significant fluorescent properties with incident laser wavelength of less than 932 nm. L-HMX has a calculated VoD value of 9425 km·s−1 and a calculated P C-J value of 41.5 GPa even 5 % higher than that of pure HMX. It is worth mentioning that the mechanical sensitivity of L-HMX crystals has been significantly reduced, and the excitation energy required for impact initiation is greater than 50 J, whereas that of pure HMX is about 6 J. The friction sensitivity is greater than 200 N. This approach may offer an efficient means to significantly enhance mechanical and thermal safety performance, while still maintaining a high energy level. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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