Preparation and Performance of Nano HMX/TNT Cocrystals

Abstract

1IntroductionIn the field of research and application of explosives, it is generallya ccepted that improving the power and reducing the sensitivity of explosives are often two opposingc haracteristics. Only an explosive with high energya nd low sensitivity can meet the application requirements adequately [1,2].I no rder to improve the performance of materials, cocrystalt echnology had been widely applied in the pharmaceutical field [3,4].N evertheless,s ince Levinthal patented the HMX/AP cocrystal explosivei n1 978 [5],t he cocrystal technology had not attracted extensive attention in the explosives arena. Nowadays, the technology of cocrystal explosives has been preliminarily researched. By cooling crystallization, Zhou obtaineda nu rea nitrate and RDX cocrystal explosive, whose explosionp erformance was superior to that of am ixtureo fu rea nitrate and RDX [6].T he HMX/ TATB cocrystal explosive wasd esigned based on crystale ngineeringa nd its crystals tructure was predicted using the polymorph predictorm ethodi namoleculard ynamics simulation by Wei [7].B ased on the research of Wei,S hen prepared the HMX/TATBc ocrystal explosive by as olvent/nonsolvent process [8].T he cocrystals tructures of HMX/NTO and HMX/NMPw ere designed using Monte Carlo simulations and first principle method by Lin [9,10].ACL-20/HMX cocrystale xplosive wasp repared by Andersonu sing the resonant acoustic mixing technology [ 11]. CL-20 and BTF cocrystale xplosive, which was prepared by Yang, was about 600 mminsize and its detonation power was predicted to be superior to that of BTF [12].B oth CL-20 and TNT were used to prepare the CL-20/TNT cocrystal explosiveb y Bolton and Yang, respectively [13,14].So far,t he cocrystal methods of explosivem ainly included solvent evaporation, cooling crystallization, solvent/nonsolvent crystallization, and resonant acoustic mixing crystal-lization. However,t he cocrystals size rangedf rom tens to hundreds of micrometers, which limited its application. It is generally accepted that ultrafine explosives possess better performance both in energy and sensitivityt han those in large size [15][16][17][18][19].I nt he aspect of highb urning rate, detonation rate and low criticald iameter,n ano or submicron explosivep articles are generally favored over the large particles [20][21][22][23].O nly little research is done on nano or submicrometer cocrystal explosives.The spray drying method had been used to prepare nano explosive using the high supersaturation in the rapid evaporation process and it had been used to prepare pharmaceutical cocrystals as well [24][25][26][27][28].B ased on this property of spray drying, nanoH MX/TNT cocrystals with high energy and low sensitivity were preparedi nt his paper.F urthermore, the structural characterization,t he formation reasons of cocrystals, impact sensitivity,a nd thermolysis of HMX/TNT cocrystals were investigated in detail.Abstract:C ocrystals of 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane( HMX) and 2,4,6-trinitrotoluene (TNT) with high energy and low sensiti...

Nano-CL-20/HMX Cocrystal Explosive for Significantly Reduced Mechanical Sensitivity

“…Alhalaweh et al [18,19] used spray drying method to prepare pharmaceutical cocrystals. Meanwhile, in our previous studies [20,21], spray drying method was also employed to prepare ultrafine CL-20/TNT and nano-HMX/TNT cocrystals with low sensitivity. To obtain CL-20/HMX cocrystal explosive with low mechanical sensitivity, nano-CL-20/HMX cocrystal explosive was prepared by spray drying method.…”

Facile Preparation and Properties Study of CL-20/TATB/VitonA Composite Microspheres by a Spray-Drying Process

“…However, existing explosives including 2,4,6,8,10,12hexanitro-2,4,6,8,10,12-hexaazaiso-wurtzitane(CL-20), 1,3,5,7teranitro-1,3,5,7-tetrazocine (HMX), and hexahydro-1,3,5trinitro-1,3,5-triazine (RDX) exhibiting high energy density, good heat resistance, stable detonation, and high detonation speed usually suffer from high mechanical sensitivity and poor shock wave sensitivity [2]. During the past decades, many studies have been devoted to the desensitization of nitramine explosives, usually using refinement, coating, and eutectic techniques to reduce sensitivity [3][4][5][6][7]. At present, coating is the most convenient way to improve the comprehensive performance of explosives, and common coating methods include water suspension method, crystallization coating method, spray-drying method, and in situ polymerization [8][9][10].…”

Prediction of the Density of Energetic Co-crystals: a Way to Design High Performance Energetic Materials

“…[4][5][6]. It should be mentioned that the techniques mainly used for the synthesis of energetic co-crystals include solvent evaporation, solvent/nonsolvent crystallization, spray drying methods and resonant acoustic mixing crystallization [7][8][9][10].…”