Thermal decomposition of bamo/ammo copolymer

Measurements of gaseous species and temperature profiles were performed to study the thermal decomposition of the copolymer of 3,3’-bis-azidomethyl-oxetane (BAMO) and 3-azidomethyl-3-methyloxetane (AMMO). Experiments were conducted at 1 ATM of argon with heat fluxes of 100 and 400 W/cm² delivered by a CO₂ laser. Gaseous samples were extracted through the use of a quartz microprobe and analyzed by a triple quadrupole mass spectrometer (TQMS). Temperature profiles were measured using the micro-thermocouple technique to investigate gas-phase reaction zones identified by the species measurements. Flame structure and surface behavior were observed using a high-magnification video system. Major species evolved from the surface were identified to be N₂, H₂CO, HCN, NH₂, H₂O, CO, CH₂CNH, and C₂H₂. Minor species include NO, CH₂, H₂, CH₂CHNH (m/z=43), CH₃CHO (44), CO₂, H₂CNH (29), C₂H₂, and CH₂. From the species measurements at both heat flux conditions, BAMOIAMMO was found to undergo simultaneous decomposition of its backbone structure, indicated by the release of high concentrations of H₂CO, H₂O, and CO, and of side chains, by the large amounts of N₂, HCN, and some hydrocarbon molecules. No gasphase reaction was identified, since most of the major species measured exhibited relatively constant concentrations in the gas-phase. The lack of a gasphase reaction was also evident from the gas-phase temperature profile that showed a relatively constant value of 800-900 K and 850-950 K at 100 and 400 W/cm₂, respectively. The effect of AMMO on the thermal decomposition of BAMO/AMMO was identified by the changes of mole fractions of some major species, surface and gas-phase temperatures, and burning rates relative to results for pure BAMO.