Investigation on Ammonium Perchlorate Based Electrically Controlled Propellants

Abstract

An experimental study exploring the ignition behavior of an electrically controlled gel monopropellant (ECGP) composed of an ionically conducting liquid polymer (polyethylene glycol) and ammonium perchlorate (AP) was conducted. Complexation of AP with PEG enabled ion transport when a voltage was applied resulting in ignition. Although the propellant was manufactures by solution casting, the final product contained no solvent as confirmed by thermogravimetric analysis. Several electrode configurations were explored which balanced or limited either oxidation or reduction at the electrodes. Other than when reduction was limited, ignition always occurred at the anode. Limiting reduction resulted in an apparent increase in the bulk resistivity of the propellant which was attributed to enhanced bubble/gas formation at the cathode. The increase in apparent bulk resistivity resulted in enhanced joule heating and a shift in ignition mechanism from predominately electrochemical to thermal. This behavior is supported by analysis of the current data and infrared temperature measurements. The temperature measurements demonstrate that the highest temperatures occur where the processes are limited. The competition between thermally and electrolytically induced ignition and combustion characteristics of the gel polymer electrolyte will be presented in this thesis.