The energetic constituents comprising the melt cast formulation Comp B, 1,3,5-Trinitroperhydro-1,3,5-triazine (RDX) and 2,4,6-trinitrotoluene (TNT), present an environmental risk toward the contamination of soils and ground water. Due to their widespread use in military munitions, contamination of training areas as well as worker exposure are significant concerns. Alternative melt cast formulations to TNT-based explosive fills, such as the recently fielded IMX-101 and 104, also have the potential to significantly impact human health and the environment.

The research objective of this project is to develop a series of melt cast, green energetic replacements based on propyl nitroguanidine for Comp B, which combined with a modified case, will provide an alternative solution to currently fielded Comp B or IMX-104 filled fragmenting warheads. It is expected that this system solution will meet the lethal performance (detonation velocity, detonation pressure, Gurney energy, and fragmentation) of an equivalent Comp B formulation in a conventional case design and exhibit reduced formulation sensitivity (responses to shock, impact, friction, and electrostatic charge) relative to Comp B while demonstrating a reduced environmental impact.

1-propyl-2-nitroguanidine (PrNQ) – a low cost, melt cast ingredient with moderate performance – is expected to exhibit little toxicity due to its chemical similarity to nitrogaunidine. Previous research results on PrNQ/1,3,5,7-Tetranitro-1,3,5,7-tetrazocane (HMX) melt cast formulations will be leveraged to guide the development of a high performance “green” energetic, which coupled with a modified case design will meet or exceed detonation performance of a comparable comp B filled case. 

Tasks to be conducted under this work include: 1) Theoretical simulation of new formulations for predicted performance; 2) sensitivity testing of new formulations to ensure safety for handling; 3) Tier 1 In vivo toxicology tests on PrNQ and a final downselected formulation; 4) detonation velocity, detonation pressure and critical diameter determinations for new formulations; 5) shock sensitivity testing by NOL large scale gap testing; 6) cylinder expansion tests for the determination of Gurney energy and 7) fragmentation analysis by mini arena test.

Replacement of RDX and TNT with less toxic HMX and PrNQ in a melt cast formulation is expected to reduce the negative impact to health and the environment during production, use and remediation. Final performance of this fill is expected to meet Comp B levels in conventional warheads, while maintaining a mild IM response.