Hydroxyl‐Terminated Polybutadiene‐Based Molding Powders as an Alternative Route for Manufacturing Pressed Polymer‐Bonded Explosives

ABSTRACT There are several drawbacks to current methods of manufacturing polymer‐bonded explosives (PBXs), including long processing times, the use of hazardous solvents, and material waste due to evaporation. Additionally, many common PBX binders are difficult to source due to a limited number of suppliers. This paper proposes an alternative approach to manufacturing energetic molding powders. This is achieved by directly mixing particles with hydroxyl‐terminated polybutadiene (HTPB), which is followed by partial curing at 70°C for controlled durations before using high‐pressure compaction to form pellets. This study investigates how the partial cure time influences the properties of the resulting mock PBXs. Results show that the cure time strongly affects binder distribution, porosity, density, compressive strength, and overall pellet homogeneity. Short cure times (2–4 h) led to binder migration toward the pellet faces and binder loss on the die walls due to the lack of solidification, while long cure times (24 h) produced expanded, sponge‐like pellets that were physically weak. Medium cure times (8–12 h) yielded the most uniform and mechanically robust pellets. This was attributed to an optimal amount of curing that allowed the HTPB to solidify enough to resist flow under higher pressure, while also retaining enough available chemical crosslinking to promote adhesion after compaction. These findings demonstrate that cure time is a critical parameter for tailoring the microstructure and mechanical performance of HTPB‐based PBXs with a high solids loading (92 wt.% equivalent HMX). This simple, microstructurally tuneable, and fast process offers a more efficient and scalable manufacturing route.