Condensed-Phase Processes during Solid Propellant Combustion. 1. Preliminary Chemical and Microscopic Examination of Extinguished Propellant Samples

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. (jes)