(694a) Crystallization of RDX during Spray Drying

It was observed in many studies that the sensitivity of explosives decreases as the crystal size of high explosives (HEs) used becomes smaller. However, the trend did not seem to extend beyond sub-micrometer range.  Explosives from 500 nm sized cyclotrimethylenetrinitramine (RDX) crystals demonstrated the least sensitivity recently. To achieve better control over the size of RDX crystals in nanocomposite microparticles from spray drying, a recent developed processing method for nanoenergetic materials, it is therefore the objective of this work to gain an understanding of the crystallization of RDX in spray drying. Detailed characterization of the microparticles, including the size and shape of microparticles, the size of RDX crystals from inner to surface region of microparticles, and the distribution of the polymeric binder will be discussed, which will shed some light on the crystallization process of RDX in spray drying. The knowledge can help improve the size controllability of RDX crystals in spray drying, moving toward nanoenergetics based explosives with optimal sensitivity.