Effect of Solid Additives on the Rheological Property of Nitroglycerin Plasticized Nitrocellulose

Abstract The rheological properties of energetic materials comprising nitroglycerin plasticized nitrocellulose were studied using rheological tests in a parallel plate rheometer. The Carreau-Yasuda equation was applied to calculate the zero-shear viscosity, and the dependence of solid additives, temperature and solvent content on zero-shear viscosity was developed. One can study flow characteristics of the energetic materials by observing the zero-shear viscosity instead of the effect of solid additives, temperature and solvent content. Additionally, the relationship between zero-shear viscosity and additives concentration was studied. The Kissinger-Akahira-Sunose (KAS) method was used to obtain the viscous flow activation energy, and the equation to describe the relationship between solid additives concentration and viscous flow activation energy was represented. The Zero-Shear Viscosity (ZSV) test showed that temperature was the predominant effect on the ZSV value at low solvent content, as the concentration of solid additives increased, the ZSV value decreased at low solvent content but increased at high one, however, there is an opposite trend when graphene concentration is above 0.1%. The viscous flow activation energy showed different changing trends with solid concentration that increased at different solvent content. The master curves were obtained by Time-Temperature Equivalence Principle, the viscosity prediction model has been established and showed a good agreement with the experimental data, compared with the test results, the viscosity prediction model is more accurate at low temperature (15°C-25°C). The obtained knowledge of the different equations will form a contribution to the research on extrusion process of this energetic material containing Cyclotrimethylenetrinitramine (RDX) and graphene, and the results obtained by this research have certain practical significance of the extrusion process for this energetic material.