Studies on Pre-Ignition Reactions of Hydrocarbon-Based Rocket Fuels Hypergolic with Red Fuming Nitric Acid as Oxidizer

Carene, norbornadiene, ethylidene norbornene, and furfuryl alcohol exhibit hypergolic ignition with red fuming nitric acid as oxidizer. Carene, when blended with norbornadiene, ethylidene norbornene, and furfuryl alcohol in appropriate proportions, exhibits synergistic hypergolic ignition with further decrease in ignition delay. In order to understand the probable mechanism of hypergolic ignition and synergy in ignition, various pre-ignition reactions have been studied by quenching the reactions and analyzing the intermediate products by Fourier transform infrared (FTIR) and gas chromatography–mass spectrometry (GC-MS) techniques. Based on the product analysis, the probable schemes of reactions have been proposed. Oxidation, nitration, and cationic polymerization appear to be the important pre-ignition reactions taking place simultaneously that are responsible for hypergolic ignition.