An experimental study on the hypergolic process enhanced by pre-ignition heat release: [AMIM][DCA]/furfuryl alcohol blends reacting with white fuming nitric acid

The hypergolic ignition behaviors of [AMIM][DCA] (1-allyl-3-methylimidazolium dicyanamide)/furfuryl alcohol (FA) blends reacting with white fuming nitric acid (WFNA) are investigated using drop test approach. Morphology results from two high speed cameras and temperature profiles from an infrared camera are combined in analyzing the hypergolic process. A typical hypergolic process observed in this work involves a mixing dominant stage, a stage with moderate temperature rising and vapor/secondary droplets emerging, and a stage with violent temperature rising accompanied by flame occurrence. Two kinds of delay times are used to characterize the hypergolic process which are found to be nonmonotonic with the variations of FA fractions. FA, though not hypergolic with WFNA, exhibits extensive pre-ignition heat release due to its physical and chemical properties, which enhances the hypergolic process of [AMIM][DCA]/FA blends with WFNA.