Development and analysis of aluminum-PTFE reactive composite material

The shortcomings of micron sized aluminum due to the oxide barrier and two phase loses pose a hindrance for its efficient use as a fuel. In this study a fluoropolymer; Teflon’s inclusion in micron sized -325 mesh aluminum is suggested as a replacement to aluminum. Aluminum Teflon based energetic material see great potential for use in pyrotechnics, propellants and even explosives. A composite with composition Al-PTFE (90-10 wt. %) is prepared through Cryomilling and is shown to be a better method of preparation as compared to room temperature milling. The prepared materials are studied to identify best conditions. The analysis methods include thermal studies both aerobic and anaerobic, Mass Spectrometry, XRD analysis and ESD experiments. The best materials are shown to retain the Teflon till higher temperatures as compared with other materials such as nano powder mixtures and milled composites of Al-PTFE, both of composition (70-30 wt. %). The milled material exhibits two exothermic peaks at 405.4°C and 540°C which correspond to the phenomena of fluorine’s interaction with the oxide to form aluminum fluoride and the phase transition into a more stable fluoride of aluminum respectively. The activation energy for these reactions are on the higher side at 145.8 and 266.4 kJ/mol. This study offers a better milling process to make more reactive composites of micron sized Al and granular Teflon (PTFE)