The research objective of this project was to develop a series of melt cast energetic replacements for Composition B based on 1,2-propyl nitroguanidine (PrNQ), which combined with an enhanced fragmenting case can provide an alternative solution to Composition B or IMX-104 filled fragmenting warheads. It is expected that this solution meets the lethal performance (detonation velocity, detonation pressure, Gurney energy, and fragmentation) of an equivalent Comp B explosive fill in a conventional case design and exhibits reduced formulation sensitivity (responses to shock, impact, friction, and electrostatic charge) relative to Composition B.

PrNQ is an easily melted ingredient chemically similar to nitroguanidine (NQ), an explosive that decomposes as it melts. PrNQ however, is a relatively poor explosive. A formulation design approach was utilized where higher performing NQ and cyclotetramethylenetetranitramine (HMX) solids were added to enhance poor PrNQ performance and to tailor processing properties of a new melt cast explosive. Munitions designed for facile fragmentation were considered for further improving the lethality of a PrNQ based explosive filled munition relative to Composition B fills.

Novel formulations comprised of PrNQ, NQ, and HMX were conceptualized, developed and safely scaled to kilogram quantities. Resulting formulations exhibited detonation properties comparable to Composition B. A large-scale fragmentation demonstration of a down-selected formulation in a conventional military munition and one designed for facile fragmentation was conducted for comparison to currently fielded munitions.

Under this program, an alternative formulation with performance approaching Composition B has been developed. This formulation could serve as a potential drop in replacement for Composition B or IMX-104 in military munitions.