Lithium-Perchlorate/Polyvinyl-Alcohol-Based Aluminized Solid Propellants with Adjustable Burning Rate

Abstract

Electrically controlled solid propellants (ECSPs) provide a completely new approach to tailor solid propellant burning rates, and an extensive range of low-hazard hydroxylamine nitrate (HAN)-based ECSPs have been developed. However, the low thermal stability and poor electrical control properties of HAN-based ECSPs limit its application. In this paper, lithium-perchlorate/polyvinyl-alcohol (PVA)-based aluminized ECSPs are prepared, and the effects of materials on the curing process and the theoretical specific impulse of the propellant are investigated. The thermal decomposition and burning characteristics were also investigated. The ratio of lithium perchlorate (${\mathrm{LiClO}}_4$)/PVA/water (${\mathrm{H}}_2\mathrm{O}$) to the molecular weight of PVA is important to the curing characteristic of lithium-perchlorate/PVA-based aluminized propellants. In addition, the degree of alcoholysis of the PVA polymer affects the curing time of the ${\mathrm{LiClO}}_4/\mathrm{PVA}/{\mathrm{H}}_2\mathrm{O}$ system. According to the results calculated using the NASA Chemical Equilibrium with Applications program, the contents of the oxidizer, aluminum, and water in the composition of lithium-perchlorate/PVA-based aluminized propellant can effectively regulate the properties of the propellant. During thermal decomposition, this propellant is more thermally stable than the $\mathrm{HAN}/\mathrm{PVA}/\mathrm{aluminum}/{\mathrm{H}}_2\mathrm{O}$-based electrically controlled propellant. The burning rates of lithium-perchlorate/PVA-based aluminized propellants at a voltage ranging from 80 to 400 V dc and pressure from 0.1 to 5.0 MPa were investigated. The results showed that the burning rate changes as a function of voltage input and pressure. The burning characteristics of the propellants can be regulated in real time by changing the electric power input.