(148d) Process Intensification for Continuous Manufacturing of Energetic Materials Via Model-Free Quality-By-Control Direct Design and Model-Based Digital Design Approaches

Crystallization is an essential process of solids manufacturing and is left unoptimized in several fields, including energetics manufacturing. Unoptimized crystallization protocols can lead to particles with undesired physical and chemical characteristics, such as particle morphology, sensitivity, detonation potential, manufacturability, and overall crystal quality. First manufactured for use in World War II, nearly a century ago, Research Department/Royal Demolition Explosive (RDX) and High Melting Explosive (HMX), have been applied to military munitions, propellants, and general explosives and continue to be two of the largest manufactured energetic materials. Although researchers have extensively studied the solubility of the common energetic materials, RDX and HMX, little work has been completed on the process intensification of RDX and HMX crystallization.

In previous work, we demonstrated the application of model-free Quality-by-Control (mf-QbC) to temperature profile development which successfully controlled the crystal size distributions/class of energetic materials. In this work, we demonstrate the combination of mf-QbC and model-based digital design to develop a robust process intensification framework for the continuous crystallization of energetic materials. Small-scale experiments completed with Crystalline showed that RDX and HMX have high solvent power (solubility) in γ-Butyrolactone and good temperature sensitivity which is desirable for crystallization control. mf-QbC allows for the reduction of experiments and exposure by utilizing feedback control strategies for desired critical quality attributes (CQAs) (Simone et al., 2015).In application with in-situ process analytical technology (PAT) tools, the two applied direct design approaches, direct nucleation control (DNC) and super saturation control (SSC), allowed for the selection of crystallization design parameters that control the desired CQAs of RDX and HMX, including but not limited to polymorphic form and overall crystal quality, and the further optimization of the selected design parameters via model-based digital design. Intensifying the industrial crystallization of common energetic materials, such as RDX and HMX, will improve the quality of manufactured energetic materials, and future process development for the manufacturing of energetic materials. Further applying this process intensification and system information to the continuous crystallization of energetic materials reduces manufacturing time, and variability during the manufacturing of energetic materials.

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