Effects of graphene oxide addition on ignition sensitivity and burning rate of NEPE propellant under rapid thermal stimulus

Abstract

With good mechanical properties and high specific impulse, nitrate ester plasticized polyether (NEPE) is potentially well suited for future high-energy propulsion systems. In this study, ignition and combustion behaviors of NEPE propellants with different graphene oxide (GO) addition contents were investigated under rapid thermal stimulus using an optical rapid compression machine (RCM). Ignition sensitivity was studied by examining the pressure evolutions and high-speed images at different temperatures and pressures. Results show that the lowest ignition temperature for all NEPE propellants decreases with the increase of pressure. At fixed pressure NEPE propellant without GO (GO0) has the lowest ignition temperature among all propellants, indicating that addition of GO decreases the ignition sensitivity of NEPE propellant. Interestingly, with the increase of GO ratio (GO/(GO + CL-20)) from 0.5 % to 2.0 %, the lowest ignition temperature presents a nonmonotonic increase. The addition of 0.5 % and 1.5 % have excellent desensitized effects, which have the potential to be applied in future propulsion systems. Moreover, the hot spots for all samples locate left or right surface of propellant, strong convective heat transfer by the rapid movement of pistons in RCM occurs. Secondly, the burning rate of GO0 is around 11 mm/s at 40 bar and 940 K, as observed by high-speed images. Note that burning rates are increased by 30–45 % with the addition of GO. In addition, simultaneous thermal analysis (STA) experiments were used to reveal the overall reactivity of the samples and NEPE propellant combustion kinetic process under rapid thermal stimulus was illustrated.