Effect of particle gradation on the rheological properties of three-component HTPB propellants

Abstract

To compare the applicability of particle gradation models commonly used in solid propellants, a variety of particle gradation models including constant-ratio gradation, maximum loading fraction gradation, and rolling gradation model, were used in the study of three-component HTPB propellants. The initial conditions were set to configure the slurries of the propellants, and the viscosity of the slurries was measured by using a rotational rheometer, and the power model was utilized to determine the rheological superiority of the slurries. The reason for the better rheological properties of the slurries is explained in conjunction with fractal theory. The results show that the Rolling gradation model is the best suited for AP single particle gradation of the three-component HTPB propellants and that its higher applicability may be related to having a higher fractal dimension number, which is positively correlated with the rheological properties. These findings help to optimize the formulation design of a three-component HTPB composite solid propellant and improve its performance.