Mechanical Properties of Composite AP/HTPB Propellants with Titania Nanoparticles

摘要

Modern advancements in chemical synthesis techniques have allowed for improved incorporation of nano-scale additives into solid rocket propellants and energetic materials. A novel method for producing titania nanoparticles directly in the binder (hydroxyl terminated polybutadiene, HTPB) of ammonium perchlorate composite propellant (APCP), termed nano-assembly, has been developed by the authors. In addition to improving propellant manufacturability and reducing safety risks associated with handling nanoparticles, this procedure improves the additive's effectiveness as a burning rate enhancer. Various methods were implemented to incorporate titania nanoparticles into APCP and the mechanical properties of each formulation were tested and compared to those of a baseline propellant with the same AP/HTPB formulation and AP size distributions. Advanced imaging techniques were applied to all particle synthesis methods to characterize particle size and particle network type and size. Uniaxial tensile testing was performed on an Instron 4411 machine at a crosshead speed of 50 mm/min (2 in/min) to measure propellant strength, ductility, and initial modulus. In all cases, the addition of nano-titania to the propellant decreased propellant strength and initial modulus, but improved ductility. The propellant formulation containing nano-assembly titania displayed the lowest propellant strength and initial modulus, but exhibited a ductility improvement of 125% over its corresponding baseline formulation.