An effective way to enhance energy output and combustion characteristics of Al/PTFE

摘要

Reactive materials of aluminum (Al) and polytetrafluoroethylene (PTFE) are attracting intense attention, which have been extensively developed owing to their high energy density (21 kJ/cm(3)) and practical applications. However, the combustion kinetics and heat of reaction are limited by the slow mass diffusion and incomplete reaction. Herein, an effective and simple way was proposed to enhance the heat of reaction, combustion and pressurization rates of PTFE/Al system by introducing ammonium perchlorate (AP) as the gas generator and oxidizer. The gaseous products from the AP decomposition can not only increase the pressure but also can further react with the produced carbon from the PTFE/Al to release more energy and gas. The significantly enhanced energy output, pressurization rate and burn rate (8863 J/g, 340 MPa/ms and 1626 m/s) were achieved for PTFE/Al by adding with 9 wt% of AP, which were much higher than that for pure PTFE/Al (2019 J/g, 29.3 MPa/ms and 260 m/s, respectively). More interestingly, the deflagration phenomenon was observed due to the high energy and pressure output. The main decomposition compounds and reaction products were further studied to understand the reaction mechanism. The strategy of adding AP in the PTFE/Al can provide efficient approach to enhance the energetic performance and promote the practical applications in propellant, heterogeneous explosives and gas generator. (C) 2020 The Combustion Institute. Published by Elsevier Inc. All rights reserved.