Improving flowability of the propellant prepared by solventless extrusion process by integration dendrimer and investigation on its thermal, sensitivity, and combustion features

A mixed nitrate ester propellant composed of nitrocellulose, nitroglycerin, triethylene glycol dinitrate, and dendrimer DP-2 was studied to explore the effects of DP-2 on the rheological properties of the propellant during the solventless extrusion process. The results showed that the apparent shear viscosity of the propellant decreased gradually with the increased mass fraction of the DP-2 from 0 wt% to 2 wt%. Additionally, it was evident that the inclusion of 0.5 wt% DP-2 leads to a notable decrease in both the apparent shear viscosity of the propellant and the torque of screw by over 50%. However, in contrast to the change in fluidity observed from 0 wt% to 0.5 wt%, the enhancement trend of propellant fluidity becomes less significant as the DP-2 content continues to increase. The effects of DP-2 on thermal properties, chemical stability, mechanical sensitivity, mechanical property, and combustion behavior of the propellant were comprehensively assessed. The results demonstrated that DP-2 exhibited promising potential as a flow modification additive for the manufacture of the propellant by solventless extrusion process.