Investigating the effect of solid fillers on mechanical and rheological properties of composite propellants

Abstract

This paper describes the theoretical analysis and experimental research work on the effect of solid fillers on composite propellant mechanical and rheological properties. The theory of the polymer rheology has been applied to model the polymer properties. The theory is extended to the composite propellants comprising a polymer binder filled with solid oxidizer and metallic fuel. The variation in oxidizer particle size and its distribution has been studied experimentally to analyze the effect on performance properties. The results of propellant viscosity and mechanical properties have been measured and discussed. It was concluded that fine ammonium perchlorate (AP) particles act as active fillers and enhance the mechanical properties of composite propellants. Viscosity decreases with an increase in the amount of fine AP particles and then starts increasing when fine proportion increases beyond ~20-25%. Similarly, elongation increases with an increase in fine AP particle size and maximum value is obtained at fine AP contents of ~25-35%. The size of the AP mean diameter also affects the mechanical properties. Both mechanical strength and elongation substantially decrease as the mean AP particle size increases. © 2013 by Begell House, Inc.