Scientific and Technical Aerospace Reports Volume 39 April 6, 2001
Scientific and Technical Aerospace Reports Volume 39 April 6, 2001
Scientific and Technical Aerospace Reports Volume 39 April 6, 2001
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interaction, the main gas products evolved are H2O, CO/N2, CH2O, NO, <strong>and</strong> N2O. Decomposition of the NVR is also observed<br />
<strong>and</strong> results in the evolution of more complex gas products than are observed in the RDX decomposition. These NVR decomposition<br />
products include: N-methylformamide, N,N-dimethylfonnamide, dimdthylnitrosamine <strong>and</strong> C3H9N (a form of amine). The<br />
rate of the decomposition reaction reaches a maximum just prior to depletion of the RDX, similar in behavior to that observed<br />
with polymer growth processes. These solid-phase decomposition processes are coupled with previously developed processes<br />
covering the liquid phase thermal decomposition of RDX <strong>and</strong> mathematical models characterizing these processes are under<br />
development. The parameters for these decomposition models are being determined from the STMBMS, optical micrograph, <strong>and</strong><br />
SEM data.<br />
Author<br />
Thermal Decomposition; Thermogravimetry; Scanning Electron Microscopy; Reaction Kinetics; Nitrogen Oxides; RDX; Chemical<br />
Reactions; Decomposition<br />
<strong>2001</strong>0025029 S<strong>and</strong>ia National Labs., Albuquerque, NM USA<br />
Real-Time Raman Spectroscopic <strong>and</strong> Ultrasonic Measurements to Monitor the HXM Beta-Delta Phase Transition <strong>and</strong><br />
Physical Changes in Thermally Damaged Energetic Materials<br />
Tappan, A. S., S<strong>and</strong>ia National Labs., USA; Renlund, A. M., S<strong>and</strong>ia National Labs., USA; Gieske, J. H., S<strong>and</strong>ia National Labs.,<br />
USA; Miller, J. C., S<strong>and</strong>ia National Labs., USA; JANNAF 19th Propulsion Systems Hazards Subcommittee Meeting; November<br />
2000; <strong>Volume</strong> 1, pp. 33-44; In English; See also <strong>2001</strong>0025025<br />
Contract(s)/Grant(s): DE-AC04-94AL-85000; No Copyright; Avail: CPIA, 10630 Little Patuxent Pkwy., Suite 202, Columbia,<br />
MD 21044-3200 HC<br />
The HMX beta-delta solid-solid phase transition, which occurs as HMX is heated near 170 C; is linked to increased reactivity<br />
<strong>and</strong> sensitivity to initiation. Thermally damaged energetic materials (EMs) containing HMX therefore may present a safety concern.<br />
Information about the phase transition is vital to predictive safety models for HMX <strong>and</strong> HMX-containing EMs. We report<br />
work on monitoring the phase transition <strong>and</strong> physical changes with real-time Raman spectroscopy <strong>and</strong> ultrasonic measurements,<br />
aimed towards a better underst<strong>and</strong>ing of physical property changes through the phase transition <strong>and</strong> during decomposition. EM<br />
samples were confined with minimal free volume in a cell in either a displacement-controlled or load-controlled arrangement.<br />
The cell was heated at a controlled rate <strong>and</strong> real-time Raman spectroscopic or ultrasonic measurements were performed. Raman<br />
spectroscopy provides a clear distinction between beta- <strong>and</strong> delta-HMX, because the vibrational transitions of the molecule<br />
change with conformational changes associated with the phase transition. Temperature-pressure dependence data for the HMX<br />
phase transition are. reported, in addition to data for the reverse phase transition as the sample was cooled. Ultrasonic time-offlight<br />
measurements provide an additional method of distinguishing the two phases because the sound speed through the material<br />
changes with the phase transition. Ultrasonic velocity <strong>and</strong> attenuation measurements also provide information about microstructural<br />
changes such as increased porosity due to evolution of gaseous decomposition products. Real-time elastic moduli data from<br />
ultrasonic experiments are reported for HMX. In addition, we report results of ultrasonic experiments for the RDX-containing<br />
EM, PBXN-109.<br />
Author<br />
Raman Spectroscopy; Real Time Operation; Ultrasonic Spectroscopy; HMX; Temperature Dependence; Damage; Solid Phases;<br />
Velocity Measurement; Phase Transformations<br />
<strong>2001</strong>0025030 Army Tank-Automative Research <strong>and</strong> Development Comm<strong>and</strong>, Picatinny Arsenal, NJ USA<br />
Effect of Additive on the Slow Cookoff of TNT<br />
Fishburn, B., Army Tank-Automative Research <strong>and</strong> Development Comm<strong>and</strong>, USA; Reddingius, B., Army Tank-Automative<br />
Research <strong>and</strong> Development Comm<strong>and</strong>, USA; Ho, Robert, Army Tank-Automative Research <strong>and</strong> Development Comm<strong>and</strong>, USA;<br />
JANNAF 19th Propulsion Systems Hazards Subcommittee Meeting; November 2000; <strong>Volume</strong> 1, pp. 45-55; In English; See also<br />
<strong>2001</strong>0025025; No Copyright; Avail: CPIA, 10630 Little Patuxent Pkwy., Suite 202, Columbia, MD 21044-3200 HC<br />
An additive, with lower thermal stability than TNT, was mixed with TNT <strong>and</strong> the formulation tested in the VCCT laboratory<br />
scale, slow cookoff test. The goal was to evaluate whether a small amount of additive could react <strong>and</strong> breech the confinement so<br />
the TNT would burn mildly. The VCCT test results displayed a statistical nature, so the relatively small number of tests doesn’t<br />
give high confidence in the evaluation. But, the results hint that a staged reaction approach can work.<br />
Author<br />
Thermal Stability; Additives; Burning Time; Trinitrotoluene<br />
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