(742e) Reaction Mechanism of Mechanically Activated Al-PTFE Composite Particles

Inclusion of low levels of polytetrafluoroethylene (PTFE) into micron-sized aluminum, by mechanical activation, can effectively alter the ignition and combustion of aluminum in propellants, explosives and pyrotechnics. Aluminum fluorination reaction kinetics can be highly dependent upon gaseous oxidizing species. The gaseous environment in which Al/PTFE particle combustion occurs can vary significantly such as propellant combustion and blast enhancement. The ignition and combustion of fuel-rich inclusion modified Al/PTFE particles are dependent upon gaseous environment, primarily species and pressure. This work aims to develop an application-specific understanding of mechanically activated Al/PTFE particle ignition and combustion. Electrically heated filament experiments are conducted at application specific heating rates in both atmospheric and high pressure, as well as oxidizing and inert gaseous environments. Reaction is observed with high-speed video and optical spectroscopy. Reaction kinetics are further explored using simultaneous differential scanning calorimetry and thermo-gravimetric analysis (DSC/TGA) coupled with evolved gas analysis using mass spectrometry and infrared spectroscopy (MS/FTIR).