466619 Cellulosic Stabilized Amorphous Solid Dispersions of HMX and CL-20

Wednesday, November 16, 2016: 4:00 PM
Cyril Magnin I (Parc 55 San Francisco)
Rajen B. Patel and Victor Stepanov, US Army, RDECOM ARDEC, Picatinny Arsenal, NJ

Amorphous solid dispersions of small organic molecules offer a number of advantages in comparison to their crystalline counterparts for practical application. When considering pharmaceuticals, glassy materials exhibit enhanced bioavailability, making them beneficial both for cost and effectiveness. In the field of energetics, amorphous solid dispersions of explosive compounds are desirable because they display exciting properties such as optical transparency, enhanced reactivity, and glass castability. While possessing useful properties, stability of amorphous solid dispersions is problematic, as the form is necessarily strained, and thus of higher energy than the ordered crystalline state. Stability can be achieved by using polymeric excipients, which inhibit crystallization, and in this application, cellulosics have been found to be particularly effective. In this work, the use of cellulosic polymers to inhibit the crystallization of a mixture of octogen (HMX) and hexanitrohexaazaisowurtzitane (CL-20) is explored. The difference in stability of nitrocellulose, cellulose acetate, and cellulose acetate butyrate stabilized dispersions of HMX and CL-20 is elucidated. Of particular interest is crystallization kinetics and glass transition temperature. These amorphous solid dispersions are characterized with the following techniques: X-Ray diffraction, Raman spectroscopy, thermomechanical analysis, differential scanning calorimetry. Overall, nitrocellulose has been found to be particular effective for inhibiting crystallization, which can be tentatively attributed to its moieties which match that of HMX and CL-20.

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