Estane‐Assisted Preparation of Submicron β‐Form HMX Particles through Antisolvent Crystallization

Abstract

AbstractOctahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX) particles were prepared through solvent‐antisolvent crystallization at room temperature by using dimethyl sulfoxide and ethanol as a solvent and an antisolvent, respectively. Estane, which has been used as a polymer binder in polymer‐bound explosives, was added to retard nucleation and inhibit crystal growth. The particles were characterized using scanning electron microscopy, X‐ray diffraction analysis, nuclear magnetic resonance spectroscopy, and thermogravimetric analysis. Owing to the nucleation at a high degree of supersaturation, thermodynamically unstable submicron non‐β‐form HMX particles were formed initially. Their morphology was changed to β‐form; the submicron size was maintained while the particles were entrapped in Estane. Estane was removed by washing with tetrahydrofuran, and the purity of the submicron β‐form HMX particles was greater than 99 %.