Comprehensive theoretical study on safety performance and mechanical properties of 3-nitro-1,2,4-triazol-5-one (NTO)-based polymer-bonded explosives (PBXs) via molecular dynamics simulation.

Abstract

3-nitro-1,2,4-triazol-5-one (NTO)-based polymer-bonded explosives (PBXs) have been widely used in insensitive munitions, but the main properties of NTO-based PBXs such as compatibility, safety performance, and mechanical properties are rarely reported. In this work, molecular dynamics simulation was carried out to study interface interactions of NTO-based PBXs, in which hydroxy-terminated polybutadiene (HTPB), ethylene-vinyl acetate copolymer (EVA), glycidyl azide polymer (GAP), poly-3-nitratomethyl-3-methyl oxetane (Poly-NIMMO), and ester urethane (Estane5703) are selected as binders. The binding energy analysis indicates that the order of compatibility is NTO/GAP > NTO/Estane5703 > NTO/HTPB > NTO/Poly-NIMMO > NTO/EVA. Radial distribution function analysis results show that the interface interaction is mainly the hydrogen bond between H atoms of NTO and O atoms of Estane5703, HTPB, EVA, and Poly-NIMMO or N atoms of GAP. The values of cohesive energy density verify that the safety is NTO/GAP > NTO/Poly-NIMMO > NTO/HTPB > NTO/EVA > NTO/Estane5703. Mechanical properties results show that GAP and EVA would improve the plasticity of the systems effectively. Furthermore, it can be found that the most favorable interactions occur between the NTO (1 0 0) crystal face and binders.