53rd AIAA/SAE/ASEE Joint Propulsion Conference, 2017, Atlanta, Georgia, 10 - 12 July 2017
Currently used rockets and missile igniter systems are mostly based on the pyrotechnic blends of fuels and oxidizers. In this study nano-sized boron was used as fuel because of its high heat of combustion, low atomic weight and high energy density. Iron oxide was used as an oxidizer and synthesized by sol-gel method by using various types of proton scavengers. In the experiments Fe(NO3)3·9H2O was used as a precursor and a wide range of proton scavengers (propylene oxide, 1,2 epoxybutane, tetrahydrofuran, tetrahydropyran, 1,4 dioxane, ammonium hydroxide and pyridine) were used to start the gelation mechanisms. The thermite mixtures were prepared by mixing nanostructured Fe2O3 xerogel samples with nano-sized boron powders. The energetic properties of boron-Fe2O3 composites were determined and the effect of proton scavengers on the textural properties and calorific value of the thermite mixtures were examined. The effect of proton scavenger on the performance and energetic properties of the samples were evaluated according to their combustion characteristics. The results showed that the surface area of xerogels is strongly dependent on the type of proton scavenger used. The heat output values of the boron/iron oxide nano thermites were determined between 1890 to 6550 J/g depending on the fuel-oxidant ratio. It was shown that both the type of proton scavenger and fuel-oxidant ratio could be used to modify the combustion performance and the structural properties of nanothermites.