This work investigates the fabrication of ammonium perchlorate composite propellants using a dual-cure (ultraviolet and thermally curable) binder via direct ink writing and compares their performance with conventionally cast counterparts. The dual-cure approach enables rapid solidification during printing through ultraviolet irradiation, followed by thermal curing to ensure complete network formation. Propellants with 70 wt% solids loading, with and without aluminum, were fabricated and evaluated in terms of mechanical properties, thermal decomposition, and combustion behavior. Dynamic mechanical analysis revealed comparable crosslink density and glass transition temperature between printed and cast binders, indicating similar network development. Mechanical property testing showed improved tensile properties for printed non-aluminized propellants, while aluminized formulations exhibited comparable behavior between manufacturing methods likely due to ultraviolet attenuation by aluminum particles. Thermal analysis confirmed similar decomposition characteristics across all formulations. Burning rate measurements demonstrated that manufacturing method had negligible influence on combustion performance. These results demonstrate that dual-cure DIW enables the fabrication of AP propellants with performance comparable to cast materials, while providing enhanced geometric flexibility and manufacturing capability.
Bazzal et al. (Mon,) studied this question.