Rheological and Mechanical Characterization of 3D-Printable Solid Propellant Slurry

Area of Science:

• Materials Science
• Chemical Engineering
• Propulsion Technology

Background:

• Development of advanced composite solid propellants is crucial for modern rocketry.
• 3D printing offers novel manufacturing possibilities for energetic materials.
• Investigating inert oxidizer replacements is key for safer propellant formulations.

Purpose of the Study:

• To characterize the rheological and mechanical properties of a 3D-printable composite solid propellant.
• To evaluate the effect of UV curing and pre-heating on propellant performance.
• To assess the feasibility of using ammonium sulfate as an inert oxidizer replacement.

Main Methods:

• Formulation of a composite solid propellant with 80% wt solids loading using polybutadiene binder and ammonium sulfate.
• Utilizing an in-house UV-A LED illumination system (385 nm) for curing.
• Conducting rheological (viscosity) and mechanical (uniaxial tensile and compression) tests.

Main Results:

• Viscosity reduction was observed for pre-heated slurry formulations.
• Mechanical properties (tensile strength and strain, compression) remained consistent with prior research.
• Temperature and solid loading percentage were identified as critical factors influencing properties.

Conclusions:

• Pre-heating resin composites can effectively reduce viscosity for 3D printing.
• The developed propellant formulation shows promise for 3D printing applications.
• Findings support the development of a 3D printer prototype for composite solid propellants.