Rheological Characterization of Energetic Materials by Rotational Testing Techniques

In production of energetic materials, the rheological behavior of propellant doughs is a key factor to identify optimum and safe conditions for processing these special compounds. The analysis of their rheological properties during mixing and extrusion stages is needed to clarify the complex interrelations between the different process parameters and the expected performance of these products, providing essential information for the possible increase of system productivity and overall product quality. In this study, the rheological analysis of triple-base propellants and a propellant simulant was carried out by a DHR-2 rotational rheometer of TA Instruments. Furthermore, different testing techniques were evaluated for appropriate characterization of these propellants. According to the results of rheological measurements, these triple-base propellants were found to correspond to shear-thinning materials (pseudo-plastic behavior). Finally, the results obtained from these experimental observations were matched to well-known constitutive empirical models to describe the mathematical relation between viscosity and shear strain rate.