State-of-the-art smokeless rocket motors utilize high energy nitramines such as RDX along with lead-based catalysts in order to meet operational requirements. Exposure to either of these integral components poses serious health risks. It is therefore important to develop new environmentally benign combustion catalysts for smokeless propellants capable of modulating the ballistic performance of emerging state-of-the-art smokeless propellant formulations.

The objective of this project is to test a series of new compounds as lead-free, burn rate modifiers in emerging minimum signature propellant formulations. The formulations efforts currently under way in the Joint Insensitive Munitions Technology Program (JIMTP) will be leveraged as a test bed for these novel catalysts.

Researchers will evaluate a series of new promising materials previously developed under Department of Defense (DoD) and National Aeronautics and Space Administration (NASA) programs. Rather than propose a new propellant development effort, the emerging insensitive munitions (IM)-driven minimum signature propellants formulation being developed under JIMTP will be leveraged. These JIMTP formulation efforts are focused on reducing the propellant sensitivity by incorporating new, less sensitive energetic solids as well as new energetic binder systems for more efficient energy partitioning. Lead-based compounds will be replaced with one or more ingredients, including dihydrobis(5-aminotetrazole-1-yl)borate (HATB), metal-organic frameworks (MOFs), and hollow proteins (Ferritin). The latter two will be incorporated as empty porous materials as well as a variety of host guest complexes with common propellant oxidizers. Initially the combustion properties of the new catalyst candidates will be evaluated against the individual ingredients in the JIMTP propellant formulations (oxidizers, binder, plasticizers, etc.) as well as in state-of-the-art minimum signature propellant formulations. The most promising catalysts will then be incorporated into the emerging formulations for ballistic evaluation. The requirement of ballistic flexibility similar to that for reduced smoke propellants that contain ammonium perchlorate will be addressed.

This project seeks to eliminate the lead-based burning rate catalyst currently used in high-performance minimum signature propellants. (Anticipated Project Completion - 2014)