Porous Cyclotrimethylenetrinitramine with Reduced Sensitivity Prepared by a Solvation–Desolvation Method

Abstract

A crystal engineering strategy has been adopted to prepare a porous high explosive, cyclotrimethylenetrinitramine (RDX). Raw RDX was crystallized with TMS, CAM, and HMPT (TMS = tetramethylene sulfone, CAM = ε-caprolactone monomer, and HMPT = hexamethylphosphoramide), forming three solvates, RDX·TMS, RDX·CAM, and RDX·HMPT, respectively. After desolvation by vacuum pyrolysis and antisolvent extraction, porous RDX containing micro- and nanoscale pores was successfully prepared. The porous RDX exhibits remarkably reduced impact, friction, and electrostatic spark sensitivity in comparison to raw RDX. A mechanism of the reduced sensitivity of porous RDX has also been proposed.

Safe Fabrication, Thermal Decomposition Kinetics, and Mechanism of Nanoenergetic Composite NBC/CL-20

“… 4 , 5 Nevertheless, the high energy level explosive is often accompanied with poor sensitivities, such as impact, friction, and electrostatic spark, which have greatly hindered the applications of CL-20 in modern military systems. 6 − 8 Hence, there is an urgent need of finding novel materials or appropriate methods to not only reduce the sensitivities but also maintain the high energy performance of explosives.…”

“…CL-20 (hexanitrohexaazaisowurtzitane) is one of the most attractive high energy density compound with promising applications in the fields of propellants and explosives . It is expected to improve the specific impulse, detonation pressure, and detonation velocity properties of munitions owing to its unique highly strained molecular cage structure. , Nevertheless, the high energy level explosive is often accompanied with poor sensitivities, such as impact, friction, and electrostatic spark, which have greatly hindered the applications of CL-20 in modern military systems. − Hence, there is an urgent need of finding novel materials or appropriate methods to not only reduce the sensitivities but also maintain the high energy performance of explosives.…”

Surface-Induced Thermal Decomposition of Energetic Cocrystal CL-20/MTNP Based on In Situ Morphology and Crystal Structure Characterizations

“…More importantly, these pores were observed to overspread the whole sample from the surface to the inside of the crystal (Figure d and h) , which turns the sample to a relatively homogeneous porous framework with the pore size and wall thickness both in a 100-nm scale. This typical morphology is considered to be benefited by the moderate decomposition gradually from the surface to inner of the CL-20/MTNP cocrystal at the relatively low pyrolysis temperature (180 °C), similar to the porous 2,2,4,4,6,6-hexanitrostilbene (HNS), cyclotrimethylenetrinitramine (RDX), and HMX prepared by the supermolecular assembly/disassembly method, which possess a potential application in composite propellant and explosive formulations for the improvement of sensitivities, combustion properties, and detonation properties. − …”

Enhanced Thermal Decomposition and Safety of Spherical CL-20@MOF-199 Composites via Micro-Nanostructured Self-Assembly Regulation

“…It is expected to improve the energy, specific impulse, and burning rate of composite solid propellants with minimum signature by replacing AP with CL-20 . Nevertheless, to the best of our knowledge, the high content of nitramine explosives often suffers from high pressure exponent and poor safety performance, which may affect the steady-state combustion process of propellants and cause accidental effects, thus further hindering the application of CL-20 in composite solid propellants. , As previously reported in the literature, the introduction of different kinds of catalysts into the oxidizer can significantly improve the thermal decomposition temperature to enhance the burning rate and reduce the pressure exponent of propellants. − Moreover, the catalyst can also be considered as a safety regulator under the prerequisite of guaranteeing energy, which can obviously improve safety performance. In composite propellant formulation, metal powders, metal oxides, organometallic compounds, new carbon materials, and various compounds are commonly used as combustion catalysts. , However, few catalysts have been currently exploited to catalyze the thermal decomposition of CL-20, which is mainly attributed to the complex thermal decomposition process of CL-20 itself, the uneven distribution and lower surface contact between solid particles, and even fewer catalytic active sites.…”