Preparation, characterization, and investigation of thermal behavior of improved HMX and RDX through coating by TNT

Simultaneous achievement of both low sensitivity and high energy is crucial in practical applications of high energetic materials such as HMX and RDX. In this work, TNT, a low-sensitive explosive, was used to improve sensitivity and thermal stability of HMX and RDX explosives. The method is based on coating HMX and RDX with TNT using solvent-anti-solvent technique. The characterization of samples was done by scanning electron microscopy (SEM), transmission electron microscope (TEM), and X-ray diffraction (XRD). The SEM and TEM images revealed that a layer of TNT was coated on the HMX and RDX surfaces. TG/DSC thermograms for HMX/TNT and RDX/TNT show that decomposition enthalpy change (ΔH) increased to 121.1 and 197.6 J/g compared to pure HMX and RDX, respectively. Fluidity test results showed that the fluidity of the samples improved from medium to good grade after coating. The impact sensitivity for HMX/TNT and RDX/TNT improved to 7.35 and 19.62 J, respectively. Also, friction sensitivity for coated HMX and RDX increased to 210.2 and 196.1 N. The electrostatic discharge experiments showed that HMX/TNT and RDX/TNT were safer than pure HMX and RDX. Therefore, the coated samples will be good candidates for energetic formulations.