Intermolecular interaction and mechanical properties of energetic plasticizer MN reinforced 2,4,6-trinitrotoluene/1,3,5-trinitrohexahydro-1,3,5-triazine molten-energetic-composite (MEC)

Abstract

Enhancing the mechanical properties is always an attractive challenge in the research area of energetic materials (EMs). In the present work, 1.5 wt.% MNsplasticizers (mononitrotoluene compounds, a mixture of 2-nitrotoluene and 4nitrotoluene) were applied for reinforcing a molten-energetic-composite (MEC) 2,4,6-trinitrotoluene (TNT)/1,3,5-trinitrohexahydro-1,3,5-triazine (RDX). Brazilian disk testing result shows that the tensile modulus of reinforced MEC increases by 26%. In order to explore the reinforcement mechanism, quantum chemistry (QC) and molecular dynamics (MD) simulation were performed to study the structural and physical properties of reinforced MEC. The basis set superposition error (BSSE) and the interaction energies of TNT, RDX and plasticizers were computed at MP2/6-311++G** levels. Compared with the weak interaction energy between RDX and TNT (−1.586 kJ/mol), the interaction energies of reinforced MEC increase massively after incorporating MNs-plasticizer. The SEM images of fractured surfaces from MECs also reveal that MNs can form layered deposits in TNT and closely surround RDX crystalline due to the presence of strong intermolecular-interaction. Besides, MD simulation results further explain that tensile modulus of (100) TNT and (100) RDX increases when introducing MNs plasticizer separately, which agree with the change trends of mechanical properties from the Brazilian disk test. This work provides a new path for studying reinforced energetic-composites by combining microscopy, mechanical test and theoretical simulations.

Polymorphism in a Nonsensitive-High-Energy Material: Discovery of a New Polymorph and Crystal Structure of 4,4′,5,5′-Tetranitro-1H,1′H-[2,2′-biimidazole]-1,1′-diamine

“…The mechanical properties of energetic materials are also an important concern toward future application. − On the basis of HMX and RDX, the basic mechanical properties of two kinds of DATNBI crystals are studied. According to the single-crystal structures of α- and β-DATNBI, the molecular model was established, and the Young modulus, bulk modulus, shear modulus, and Poisson’s ratio were obtained by molecular dynamics (MD) simulation.…”