Download or read book Condensed Phase Processes During Solid Propellant Combustion 3 Preliminary Depth Profiling Studies on XM39 JA2 M9 M30 and HMX2 written by and published by . This book was released on 1994 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes preliminary depth-profiling studies on the chemical changes in the burned layers of propellant samples that have been burned in air, then quenched by dropping them into water. The changes studied described here are mainly those observable by infrared spectroscopy using an infrared microscope. Depth-profiling is obtained either by examining the cross section of a burned propellant sample or by abrasive blasting small amounts of material from the burned surface and examining the remaining surface in the infrared microscope. The propellants and compositions studied include XM39, JA2, M9, M30, and HMX2. For the nitramine-binder compositions XM39 and HMX2, the surface layers seem to consist of a layer of molten oxidizer (RDX or HMX) tens to hundreds of micrometers thick, overlaid by a 10- or 20-micrometer-thick layer of binder and/or its decomposition products. In the case of the nitrate ester compositions JA2 and M9, the chemical changes observable by infrared spectroscopy seem to be very near the surface, within approximately 10 micrometers. This is in agreement with our scanning electron microscope observations and with results in the literature.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1994 with total page 1368 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1994 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Condensed Phase Processes During Solid Propellant Combustion 1 Preliminary Chemical and Microscopic Examination of Extinguished Propellant Samples written by Michael A. Schroder and published by . This book was released on 1990 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Burning propellant samples are quenched, and the burned surfaces are examined microscopically and by chemical analysis. Studies are in progress on a series of propellants including XM39, M30, JA2, RDX, HMX, HMX/PU, and HMP/polyester ('HMX2') compositions. Preliminary results on quenched samples of XM39 burned at low pressures show evidence of a liquid layer approximately 100-300 micron thick. SEM examination reveals little if any evidence of degradation below this liquid layer. GCMS analysis shows that the stabilizer is depleted considerably in the surface layers of quenched samples, presumably by reaction with nitrogen oxides formed by decomposition of RDX and NC. HPLC results show that there is a significant increase the very small amounts possibly present as impurities. Keywords: Extinguishment, Quenched-sample analysis, Propellants, Explosives, Nitramines, Nitrate esters, Combustion. (jes).
Download or read book Condensed Phase Processes During Solid Propellant Combustion Part 2 Chemical and Microscopic Examination of Conductively Quenched Samples of RDX XM39 JA2 M30 and HMX Binder Compositions written by and published by . This book was released on 1992 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: Burning propellant samples were quenched, and the burned surfaces were examined microscopically and by chemical analysis. Studies are in progress on a series of propellants including XM39, M30, JA2, RDX, and HMX-polyester compositions. The results to date are consistent with the idea that at least at low pressures (below 2.0 MPa), a liquid layer forms during combustion of most of the propellants, with the possible exception of JA2; scanning electron microscope examination shows the existence of a liquid layer but does not provide evidence of degradation below this layer. The effect of composition and pressure on this liquid layer is discussed. Further gas chromatography mass spectrometry analysis confirms our earlier result that at least in the case of XM39, the stabilizer is depleted considerably in the surface layers, presumably by reaction with nitrogen oxides formed by decomposition of RDX and NC. Further high performance liquid chromatography results confirm our earlier result that for XM39, HMX2, and RDX (which contain the cyclic nitramines HMX and RDX), there is a significant increase in concentration of the mechanistically significant nitrosamines MRDX and DRDX over the very small amounts possibly present as impurities In RDX and HMX. FTIR-PAS results provide evidence for condensed-phase reaction in M30 and JA2.
Download or read book Condensed phase Processes During Solid Propellant Combustion written by and published by . This book was released on 1992 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Condensed Phase Processes During Solid Propellant Combustion V Further Observations on Depth Profiling of Burned Surfaces of XM39 and M43 Propellants written by and published by . This book was released on 1996 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Samples of XM39 and M43 propellants that have been self-extinguished at low pressures have been examined under a Scanning Electron Microscope (SEM). The results of this examination suggest that the surface layers of burning HMX/RDX propellants consist of a thin, smooth layer presumably made up of binder and its decomposition products. This layer overlies a thicker layer of crystalline, bubble-containing material that is presumably mostly solidified or recrystallized (liquified during combustion) RDX oxidizer. Photoacoustic Fourier Transform Infrared (FTIR) spectra of some burned/extinguished samples of XM39, JA2, and RDX are also reported and discussed. Based on our results to date, presented in this and previous reports, some suggestions for modelers of nitramine propellant combustion are presented. It is suggested that, if practicable, formation and subsequent decomposition of nitrosoamines, such as MRDX and DRDX, should be included in the condensed-phase chemistry models of deflagration of RDX and of RDX-based propellants. Also, the mathematical framework should include provision for formation and growth of bubbles in the liquid layer as a result of both thermal decomposition and vaporization of RDX.
Download or read book Condensed Phase Processes During Solid Propellant Combustion 4 Chemical and Microscopic Examination of Laser Irradiated Propellant Samples written by and published by . This book was released on 1995 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: The surfaces of laser-irradiated gun propellants have been examined by scanning electron microscopy (SEM) and Fourier Transform Infrared (FTIR) microscopy. The results suggest that the laser-irradiated surfaces exhibit chemical and physical changes similar to those exhibited by the burned surfaces of propellant samples, the combustion of which have been quenched short of completion. Some possible implications of this for combustion and for the modelling of laser ignition are discussed. jg p.3.
