The low vapor toxicity of ionic liquids (ILs) make them attractive replacements for hydrazine in rocket applications.  However, ILs will fail to fulfill their revolutionary promise unless toxic oxidizers like HNO3 or N2O4 can be replaced with safer alternatives.  By their very nature all rocket oxidizers are hazardous and so reducing those hazards, even though the resulting materials might not be completely harmless, is at the heart of green initiatives in propulsion.  The corrosivity of nitric acid is well known and while N2O4 is much less corrosive it combines high toxicity with high vapor pressure.  A significant step to a lower toxicity bipropulsion system would be the demonstration of hypergolicity (spontaneous ignition) between an IL and a safer oxidizer.  Outside of cryogens high performing hydrogen peroxide seems to be especially promising, with its less toxic vapor and corrosivity and its environmentally benign decomposition products.  Design strategies for prospective ILs are discussed.

Green bipropellants:  Ionic liquids that are hypergolic with hydgrogen peroxide

243rd National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.