On the Reliability of Sensitivity Test Methods for Submicrometer‐Sized RDX and HMX Particles

Abstract

Submicrometer‐sized RDX and HMX crystals were produced by electrospray crystallization and submicrometer‐sized RDX crystals were produced by plasma‐assisted crystallization. Impact and friction sensitivity tests and ballistic impact chamber tests were performed to determine the product sensitivity. Rather than reflecting the quality of the particles, we found the sensitivity tests to be unreliable for submicrometer particles. The used impact test was not accurate enough, while in the friction and ballistic impact chamber tests the submicrometer‐sized crystals were distributed among the grooves of the porcelain plate or among the grains of the sandpaper used in these tests. These observations stress the need for revisiting the current standards used for determining the hazardous properties like friction and impact sensitivity of energetic materials in the case, where the sample consists of submicrometer‐sized crystals. Recommendations were suggested to develop new test methods that only use the interactions between the particles and therefore allow the application of sensitivity tests for submicrometer/nano‐sized energetic materials.

Bioinspired Fabrication of Insensitive HMX Particles with Polydopamine Coating

“…Because of the increasing attention on insensitive munitions for improved safety and high performance, there is ag rowing demand for insensitive highe xplosives [1].H MX (C 4 H 8 N 8 O 8 ,c yclotetramethylenetetranitramine) is one of the most importante nergetic materials. With its high detonation velocity, detonation heat, and detonation pressure, HMX particles are widely applied in PBX (plastic bondede xplosive),s olid rocket propellants, and civil explosive materials [2].H owever, industrial HMX particles still have limitations in insensitive munitions applications, such as high mechanical sensitivities and poor adhesive properties with other materials in the PBX [3].T oo btain insensitive HMX particles, an umber of studies focusedo nt he relationship betweenp article sizes, shapes, polymorphs, coatings, and the mechanical sensitivities [4][5][6],r espectively.A lthough providinga ninsensitive coating (wax, thermoplastic polyurethane and TATB) on HMX particles [7][8][9] was ac onventional and facile method, those inhomogeneous, incompletely covered and thick coatings still could not be scaled up. Therefore, HMX particles with at hin and uniform coating, combined with insensitivity,e xcellent adhesive properties, and high performance are important for the development of insensitive munitions.…”

Synthesis, crystal structure, and thermal properties of Ni(NH3)4(AFT)2

“…Although the peak temperature of compound 1 is lower than that of Zn(NH 3 ) 4 (AFT) 2 (320.58 °C), 34 it is higher than those of Cu(NH 3 ) 4 (AFT) 2 (310.92 °C), Cu(C 3 H 6 N 2 H 4 ) 2 (AFT) 2 (219.08 °C), 33 RDX (219 °C) and HMX (275 °C). 35 These data indicate that compound 1 possesses high thermal stability.…”

The longstanding challenge of the nanocrystallization of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX)

“…For a deeper understanding of the crystallization of energetic materials at the nanoscale, a better comprehension of the resulting powder is needed. Beyond the issue of the reliability of the sensitivity values of energetic materials at the nanoscale [ 132 ] and tested at the laboratory scale [ 133 ], the pyrotechnic community should actively discuss the repeatability, the agglomeration of particles and the particle size distribution with accurate peak fittings.…”