Bamo - Thf Copolyether Coated Modification Hmx And Its Performance Study

In order to improve the mechanical properties, safety performance and processing properties of high solid propellant with high energy and high solid content, one of the solid components of the formula-nitroamine explosives can be chosen to be coated with less sensitive materials. However, the traditional addition of inert coating materials will reduce the energy of solid propellant. In this paper, BAMO-THF copolyether was selected to coat HMX to eliminate the negative effects which caused by coating materials. The high energy property of BAMO-THF copolyether could effetctively reduce the friction and impact sensitivities of HMX without compromising the solid propellants energy.Firstly, the BAMO-THF copolyether/HMX compounds were obtained using BAMO-THF copolyether as coating material, adding DOS as plasticiser, MAPO as cross linker and TDI as firming agent by phase separation method. The results showed that-0.085MPa and35℃were the best experiment factors. Surface morphology was characterizatied by SEM. Particle size distribution curves demonstrated that the D50of the the BAMO-THF copolyether/HMX compounds increased5.59μm after coated. And the absorption peak at2103.86cm-1in the infrared absorption curve belongs to -N3stretching frequency in BAMO-THF copolyether, and the antisymmetric stretching vibration mode of-NO2group in HMX occured obvious red-shift (from1530.50cm-1to1524.23cm-1) after being coated, suggesting that hydrogen bonding interaction took place during the coating process. What’s more, the surface elemental composition of the compounds and coated degree(63.51%) were studied by Energy Dispersive Spectrometer (EDS).Secondly, well dispersed HMX particles coated with BAMO-THF copolyether were obtained successfully by slurry-emulsion-distillation method. And the influence factors of experimental process such as the ratio of water to ethyl acetate, surface active agent and stirring speed were investigated systematically. The possible coating mechanism was also discussed. Surface morphology was characterizatied by SEM. Differential Scanning Calorimetry (DSC) curves under different heating rates showed that the activation energy of Ea and self-ignition temperature changed a little after coating. Shown from particle size distribution curves, the D50of the compouds increased12.86μm and the particle size distribution became narrow. EDS results indicated that the coated degrees were52.46% after coated.Finally, double layer coating technology which should wash the outer coating layer was used to prepare BAMO-THF copolyether/HMX compounds. The obtained optimum coating conditions are vacuum degree:-0.085MPa, melting temperature:85℃, stirring speed of emulsion:2000R/min, stirring speed of recrystallization:1000R/min. Seen from the particle size distribution curve, the D50of coated samples increased2.44μm, which confirmed that the modified samples had good dispersion. SEM、 TEM results showed that a uniform and compact coating layer was on their surface. The coated degrees reached to72.22%.