The hypergolic interaction between N,N,N′,N′- tetramethylethylenediamine (TMEDA, (CH3)2NCH 2CH2N(CH3)2) and nitric acid was studied by several different experimental techniques. The gaseous species from condensed- and gas-phase reactions between TMEDA and nitric acid (90% HNO 3) were analyzed by a confined interaction setup, coupled with a Fourier transform infrared (FTIR) spectrometer. The species identified include TMEDA dinitrate, dimethylnitrosamine (CH3)2NNO, dimethylformamide (CH3)2NCHO, CH2O, H 2O, NO2, HONO, NO, CO2, N2O, and CO. The solid residue from the condensed-phase reactions between TMEDA and 90% HNO3 was studied by using a confined rapid thermolysis (CRT) coupled with FTIR spectroscopy and time-of-flight mass spectrometry. On the basis of the product analysis, the preignition reactions between TMEDA and nitric acid are discussed. The initiation reaction is a condensed-phase, exothermic salt formation reaction. At elevated temperatures, the thermal decomposition of nitric acid produces NO2, which abstracts a hydrogen atom from TMEDA and causes a series of further reactions involving the formation of dimethylnitrosamine and aldehydes. The acid-catalyzed decomposition of TMEDA dinitrate also plays an important role in the preignition reactions. High-speed videos were acquired to visualize the preignition, ignition and postignition events in a drop test when a fuel drop impinged on a pool of 90% HNO 3. In addition, temperature profiles were obtained in gas and condensed phases using coated fine-wire thermocouples.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Fuel Technology
- Energy Engineering and Power Technology