Comminution of energetic materials in viscous binder components with high solid loadings

Wet comminution enables the production of very fine energetic particles direct in binder components. Besides the processing of energetic materials, the general high viscosities of binder materials are challenging. Furthermore, applications require high solid mass fractions which can additionally increase the suspension viscosity. In this work the wet comminution of energetic particles in binder materials was investigated. Particularly, the grinding of octogen (HMX) in hydroxyl-terminated polybutadiene (HTPB) was investigated with the focus on increasing the solid concentration. The milling process could be achieved with HMX-mass fractions of up to 20 wt.-% whereby very fine energetic particles with monomodal narrow size distributions were produced. Important product properties of the energetic particles and the suspensions were characterized. An influence of the grinding on enhanced material sensitivities and of the solid fraction on the rheological behavior in steady-shear flows could be shown. Thereby, the viscosity increase under low shear rates in suspensions with 20 wt.-% indicated a crucial behavior for the development of innovative applications as well as the comminution process. Furthermore, the application of the grinded HMX in HTPB in Plastic Bonded Explosive (PBX) formulations was investigated.