A Quality Control Tool to Study the Influence of Aluminium Powder Variationat Premix Level Propellant Slurry by Thermal Characterization

Composite solid propellant is considered a heterogeneous mixture in which solid particles are embedded in a polymeric matrix (binder). There are many kinds of polymers used in binder composition which acts as a binder for the solid particles and also as a fuel during the propellant combustion. The solid particles of propellant are composed of an oxidizer, usually ammonium perchlorate (AP), and a metallic fuel is used to increase the temperature of the combustion products. In addition to the basic components, other ingredients like plasticizers, bonding agents and combustion catalysts are added in the propellant formulation. Aluminium powder is widely used as a metal fuel in propellants, explosives, pyrotechnics, and hydrogen production because of its high-energy density, high combustion enthalpy, and friendly nature for the ecosystem. The thermal decomposition kinetics of ammonium perchlorate (AP) /hydroxyl-terminated-polybutadiene (HTPB) /aluminium propellant slurry samples, the AP/Al/HTPB solid propellant, with copper chromite as burning rate catalyst at micro scale with two different formulations were studied by thermal analysis techniques at different heating rates curves in dynamic nitrogen atmosphere. In order to modify the propellant properties additives will be added in small quantities. A propellant composition of 86 and 85 % wt/wt solid content with 14 and 15 wt- % of a binder component mixture were used in this study. The present paper discusses the thermo chemical properties and thermal decomposition reactions of AP-HTPB-Al propellant prepared with different formulations. The activation energy is found lower when aluminium is increased in the propellant formulation. The results showed that there is a significant change is noticed in the HHV when the aluminium content is varied in the premixed propellant slurry and the changes in the formulations can be detected by Bomb calorimetry technique.