Sodium iodide: A trigger for hypergolic ignition of non-toxic fuels with hydrogen peroxide

Abstract

In recent years, rocket scientists have devoted attention to the development of environmentally friendly hypergolic propellants for propulsion of space vehicles. In this study, sodium iodide a trigger compound was investigated to improve the hypergolic performance of green fuels viz., ionic liquid, 1-ethyl-3-methyl imidazolium cyanoborohydride ([EMIM][BH3CN]), and zwitterion, 1-methyl imidazolium borane (MIMBH3) with 95% H2O2 green oxidizer. A 9 wt.% of sodium iodide in [EMIM][BH3CN] exhibited an ignition delay time of ~75 ms. However, 9 wt.% of sodium iodide in the blend of [EMIM][BH3CN]:furfuryl alcohol (1:1 wt./wt.%) revealed an ignition delay time of 56 ms. These ignition delay times were a hundred times lower than the neat fuel of [EMIM][BH3CN]. Interestingly, the MIMBH3 exhibited a shorter ignition delay time was about 25 ms, with the addition of < 3 wt.% of sodium iodide. Moreover, furfuryl alcohol blended with ionic liquid also improved the performance of hypergolic bipropellants.