(619d) PAT Controlled Crystallization of Energetic Materials

The high explosive crystal quality, size and morphology can significantly affect their initiation sensitivity. Properties such as crystal shape, size, voids and inclusions can be directed by controlling the crystallization conditions. Improved control of process parameters is required to achieve the desired crystal characteristics since the control of these properties is difficult at the production scale of high explosives and results in large particle size distribution, requiring milling to achieve different class sizes and other potential material rework. When optimizing the size and shape of the crystals during batch crystallization, it is often preferred to operate within the metastable zone to avoid undesired nucleation. In this work RDX seeds are generated using ultrasound at different saturation temperature within the MSZ. Those seeds are controlled to follow a supersaturation profile within the MSZ to promote the growth rate and keep the rate of nucleation low. Process Analytical Technology (PAT) was used to control the crystallization process through real-time measurements using ATR-FTIR, FBRM and PVM tools.