Decomposition of nitromethane is reported over the range of 115- 180°C and 0.6-8.5 GPa. About 5 [mu]g of nitromethane is compressed with a diamond-anvil cell, heated to the point that reaction occurs, and held typically 10-20 minutes at the reaction temperature. The cell is cooled and the volatile contents of the cell are frozen as a thin layer in vacuo and an infrared absorption spectrum is recorded. The three volatile products observed are N2O, CO2, and water, with N2O production peaking at 1.5 GPa, 135°C, and 35% of NME; CO2 production peaking at 3.5 GPa, 135°C, and 65% of NME, and water yields at 20-50% of NME at the highest pressure measured, 8.5 GPa and 175°C. Water yields were difficult to quantify due to background contamination. Results indicate three different reactions for solid NME dependent primarily on the pressure of the reaction, and that fluid NME does not decompose at 0.6 GPa and 175°C, although the solid decomposes readily at 1.1 GPa and 120°C. The authors conclude that, while various decomposition mechanisms are possible, the initial step CH3NO2 → /center dot/CH3 + /center dot/NO2 is very unlikely. 14 refs., 5 figs.

This thesis outlines the bottom-up development of a high pressure, high density initiation mechanism for nitromethane decomposition. Using reactive molecular dynamics (ReaxFF), a hydrogen-abstraction initiation mechanism for nitromethane decomposition that occurs at initial supercritical densities of 0.83 grams per cubic centimeter was investigated and a mechanism was constructed as an addendum for existing mechanisms. The reactions in this mechanism were examined and the pathways leading from the new initiation set into existing mechanism are discussed, with ab-initio/DFT level data to support them, as well as a survey of other combustion mechanisms containing analogous reactions. C2 carbon chemistry and soot formation pathways were also included to develop a complete high-pressure mechanism to compare to the experimental results of Derk. C2 chemistry, soot chemistry, and the hydrogen-abstraction initiation mechanism were appended to the baseline mechanism used by Boyer and analyzed in Chemkin as a temporal, ideal gas decomposition. The analysis of these results includes a comprehensive discussion of the observed chemistry and the implications thereof.

A detailed chemical mechanism describing ignition of high-temperature pure gaseous nitromethane was compiled and tested using shock were n the tange 1000 to 1600 K and 1 to 10 atm. Measurements were made of the timew efolution of the pressure at the end wall, as well as of dte simultaneous pressure and NO avsorption a short, fixed distance from the end wall. Mass and infrared spectoscopy were used to identify the final products. In the reaction mechanism proposed, initiation starts with the C-N bond breaking which yields CH3 and NO2. Methoxy and CH2NO2 proposed, initiation starts with the C-N bond breaking which yields CH and NO2. Methoxy and CH2NO2 radicals then propagate the reaction through two major parallel pathways, both producilng CH2O. Formaldehyde is then reduced to HCO and carries the rraction towards completion. The radical reactions do not release enough energy to compensate for the energy consumed in breaking the C-N bond. Although most of the radicals reach their maximum concentration early lin the reaction process, ignition does not occur until virtually all f the nitromethane is consumed. THe calculations show thar the nitro group is the key to explosion: NO2 produces OH through its reacxtion wilth H radicals. Hydroxyl reactions, which are fast and exothermic, lead t an accelerated consumption to the explosive with heat release. Comparison with the experiments shows that the mechanism predicts correct induction times for the pressure and tempetature range of dthe experiments. Keywords: Chemical kinetics; Explosives.

Developments in experimental methods are providing an increasingly detailed understanding of shock compression phenomena on the bulk, intermediate, and molecular scales. This third volume in a series of reviews of the curent state of knowledge covers several diverse areas. The first group of chapters addresses fundamental physical and chemical aspects of the response of condensed matter to shock comression: equations of state, molecular-dynamic analysis, deformation of materials, spectroscopic methods. Two further chapters focus on a particular group of materials: ceramics. Another chapter discusses shock-induced reaction of condensed-phase explosives. And a final pair of chapters considers shock phenomena at low stresses from the point of view of continuum mechanics.

This series provides the chemical physics field with a forum for critical, authoritative evaluations of advances in every area of the discipline. Volume 131 includes chapters on: Polyelectrolyte Dynamics; Hydrodynamics and Slip at the Liquid-Solid Interface; Structure of Ionic Liquids and Ionic Liquid Compounds: Are Ionic Liquids Genuine Liquids in the Conventional Sense?; Chemical Reactions at Very High Pressure; Classical Description of Nonadiabatic Quantum Dynamics; and Non-Born Oppenheimer Variational Calculations of Atoms and Molecules with Explicitly Correlated Gaussian Basis Functions.

Bretherick's Handbook of Reactive Chemical Hazards, Eighth Edition presents the latest updates on the unexpected, but predictable, loss of containment and explosion hazards from chemicals and their admixtures and actual accidents. The extensively cross-referenced book enables readers to avoid explosion and loss of containment of chemicals. Primary and more specialized sources are easily traced, and this new edition includes available record updates, also adding a number of new records. In this newly updated and expanded edition, the content is presented in a clear and user-friendly format. - Includes new pure compound/class of compounds records and updates on all existing records - Presents a worldwide unique reference work on chemical reactive hazards - Lists important hazardous reactions and includes references to real chemical incidents - Provides guidelines on the safe use and handling of chemicals In the lab and industry