A Mechanism for Ignition of High-Temperature Gaseous Nitromethane - The Key Role of the Nitro Group in Chemical Explosives.
Abstract
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 08, 1985
- Accession Number
- ADA157355
Entities
People
- D. Bogan
- D. Hsu
- E. Oran
- R. Guirguis
Organizations
- United States Naval Research Laboratory