Investigation and Characterization of Water-Recrystallized Croconic Acid

Report No. ARL-TR-7910
Authors: Sarah Isert; Jennifer A Ciezak-Jenkins
Date/Pages: December 2016; 28 pages
Abstract: A high-pressure phase of croconic acid is being investigated as a novel energetic material. When pressed at high pressures (>5.5 GPa), as-received croconic acid transforms into a β -phase that is recoverable to ambient conditions. This phase has a higher density and heat of combustion than the as-received material. Rectangular crystals, which are darker than the original powder, can be observed in the recovered material and are thought to indicate formation of the β -phase. When croconic acid is recrystallized from water at ambient conditions, similar appearing crystals are observed. We performed experiments to investigate the plausibility of recovering the β -phase croconic acid from water recrystallization as an alternative to the high-pressure synthesis. Thermal analysis, bomb calorimetry, X-ray diffraction, and Raman spectroscopy were performed on water-recrystallized croconic acid to determine whether or not it is the β -phase. We found that the water-recrystallized material is not the β -phase and at present high pressures is still required for β -phase formation.
Distribution: Approved for public release
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Last Update / Reviewed: December 1, 2016