Study On The Process Of HMX Coated By TATB

Cyclotetramethylene tetranitramine (HMX) as a kind of high energy explosive due to its desirable properties, such as high density, high detonation velocity and good thermal stability, was applied in various propellants and military warheads. While its high mechanical sensitivity and bad safety were obstructing its further application. In order to deal with the problems above, the method of solution evaporation under vacuum was adopted to produce the explosive of HMX coated with TATB. The preparation of coating was studied and the mechanism of caoting was discussed. In addition, the structure of the explosive which produced in the best conditions was characterized and the performance was tested.Single factor method was applied to systematically analyse the factor influencing on the coating effect, such as surfactants, binder, the size of HMX, the size and amount of TATB and the evaporation temperature. The optimal reaction conditions as follow were obtained by orthogonal experiments:Tween-20,2% Estane-5703, HMX with size of 50μm, 12% TATB with size of 0.7 μm, and evaporation temperature of 60 ℃.The structure of the explosive of HMX coated with TATB was characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD).The performance of the explosive of HMX coated with TATB which produced in the optimal reaction conditions was tested and analyzed by thermogravimetry (TG), differential scanning calorimeter (DSC) and mechanical sensitivity testing. The results were as follows:the surface of HMX are coated by TATB shell with the coverage close to 100%; the coated explosive was still with the stable β phase, the same as HMX; the decomposition temperature of the explosive of HMX coated with TATB was about 1 ℃ higher than HMX and both the impact sensitivity and fraction sensitivity of the coated explosive were lowed to 0.The results above indicate that the explosive of HMX coated with TATB produced in the optimal reaction conditions owns perfect properties which have balanced high explosive performance and low sensitivity of energetic materials.