An Investigation into the Effects of Additives on Crystal Characteristics and Impact Sensitivity of RDX

Abstract Additives are one of the most important factors that greatly affect the crystal characteristics of the high energy compound hexahydro-1,3,5-trinitro-1,3,5-s-triazine (RDX, C3H6N6O6) and they have an influence on impact sensitivity. In this article, a growth morphology method was applied to obtain the crystal habit of RDX in a vacuum as well as the morphologically important faces, and molecular dynamics simulations were applied to calculate the interaction energy between these crystal faces and additive molecules for prediction of the additive-effect crystal habits of RDX. On this basis, crystal characteristics including crystal morphology, aspect ratio, and total surface charge were investigated. Then the particle size and surface electrostatic voltage of the samples from recrystallization were analyzed experimentally. The impact sensitivity test indicated that acrylamide, which could enhance the regularity and degree of sphericity of RDX crystals and effectively reduce the surface static electricity of RDX, was successful in reducing the impact sensitivity of RDX as an additive for crystallization. The above experimental results were in good agreement with the conclusions based on the theoretical calculations. Keywords: additivecrystal characteristicsgrowth morphologyimpact sensitivitymolecular dynamicsRDX Notes a All energies are in kilojoules per mole, distance is in angstrom, and area is in angstrom squared. b Total facet area. a Surface charge of each crystal slice in a unit cell. b Elementary charge; that is, the electric charge carried by a proton, 1.6 × 10−19C. c Surface area of the crystal face (h k l) in a unit cell. d Surface charge of the crystal face per unit area.