{"93061":{"#nid":"93061","#data":{"type":"event","title":"(08-0821) Dr. Elizabeth Glascoe, Lawrence Livermore National Lab","body":[{"value":"\u003Cp\u003EDr. Elizabeth Glascoe, Lawrence Livermore National Lab\n\u003C\/p\u003E\n\u003Cp\u003EPressure Dependent Decomposition Kinetics of the Energetic Material HMX\n\u003C\/p\u003E\n\u003Cp\u003EIn this study we precompressed an energetic molecular crystal C4H8N8O8, HMX, up to pressures of 4 GPa and monitored the corresponding thermal decomposition kinetics using time resolved Fourier transform infrared, FTIR, spectroscopy. Decomposition rates were determined from the slope of decaying HMX vibrational IR intensities vs. time. Using these rates Arrhenius parameters were then determined using the extended Prout-Tompkins nucleation-growth model. At approximately 1 GPa we find an inflection point in the decomposition rate where the prior positive slope changes sign and applied pressure begins to retard thermally induced reactions. These results indicate that the phase transition in HMX plays a minor role in the thermally induced kinetics. We attribute 0 to 1 GPa rate acceleration to pressure enhanced autocatalysis whereas greater than 1 GPa rate deceleration is attributed to an increasing barrier to bond cleavage, which would result in an increase in volume. \n\u003C\/p\u003E\n\u003Cp\u003E1. A.K. Burnham and R.L. Braun. \u0022Global Kinetic Analysis of Complex Materials\u0022 Energy and Fuels, 1999, 13, 1.\n\u003C\/p\u003E\n\u003Cp\u003EThis work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.\n\u003C\/p\u003E\n\u003Cp\u003EFor more information contact \u003Ca href=\u0022mailto:christine.payne@chemistry.gatech.edu\u0022\u003EProf. Christine Payne\u003C\/a\u003E (404-385-3125).\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"Dr. Elizabeth Glascoe, Lawrence Livermore National Lab\n\nPressure Dependent Decomposition Kinetics of the Energetic Material HMX\n\nSpecial Physical Chemistry Seminar","format":"limited_html"}],"field_summary_sentence":[{"value":"Dr. Elizabeth Glascoe, Lawrence Livermore National Lab"}],"uid":"27275","created_gmt":"2008-07-18 00:00:00","changed_gmt":"2016-10-08 01:57:20","author":"Shirley Tomes","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2008-08-21T16:00:00-04:00","event_time_end":"2008-08-21T17:00:00-04:00","event_time_end_last":"2008-08-21T17:00:00-04:00","gmt_time_start":"2008-08-21 20:00:00","gmt_time_end":"2008-08-21 21:00:00","gmt_time_end_last":"2008-08-21 21:00:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"85951","name":"School of Chemistry and Biochemistry"}],"categories":[],"keywords":[{"id":"89","name":"chemistry"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cstrong\u003EShirley Tomes\u003C\/strong\u003E\u003Cbr \/\u003EChemistry \u0026amp; Biochemistry\u003Cbr \/\u003E\u003Ca href=\u0022http:\/\/www.gatech.edu\/contact\/index.html?id=st81\u0022\u003EContact Shirley Tomes\u003C\/a\u003E\u003Cbr \/\u003E\u003Cstrong\u003E404-894-0591\u003C\/strong\u003E","format":"limited_html"}],"email":[],"slides":[],"orientation":[],"userdata":""}}}