Rheological Behavior of Concentrated GAP/ AP Propellant Suspensions Plasticized by Diglycerol Tetranitrate

Abstract

Concentrated GAP/AP propellant suspensions with different solid contents and molecular masses of GAP were prepared, in which diglycerol tetranitrate (DGTN) was the energetic plasticizer. The steady shear measurements were conducted using a rheometer to examine the influences of component characteristics, particle gradation and temperature on rheological behavior. Results indicate that the GAP/DGTN mixture is Newtonian viscous and concentrated GAP/AP suspensions are pseudoplastic fluids. The Ostwald -De Waele model and the Arrhenius -de Guzman equation are utilized to compare the pseudoplastic behavior and the viscosity-temperature dependence of concentrated suspensions, respectively. The apparent viscosity is exponentially related to solid content and the pseudoplastic behavior gradually increases with solid content revealed by the decreasing power law index (n). Additionally, larger particle size of AP, smaller molecular mass of GAP, or lower temperature make possible the reduced apparent viscosity. Suitable particle gradation reduces the apparent viscosity to the desired value.