Pyrolysis and kinetic modeling study of tetramethylethylenediamine: A potential green propellant

Tetramethylethylenediamine (TMEDA) is a promising green propellant that has been studied as a substitute for hydrazine. An in-depth study of the TMEDA thermal decomposition mechanism is important for future applications in engines. In this work, pyrolysis experiments of TMEDA were carried out in an atmospheric jet-stirred reactor (JSR) from 610 to 1000 K. Abundant intermediate species were analyzed and quantified by synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS) and gas chromatography (GC). The results show that the pyrolysis of TMEDA mainly produces hydrocarbons, amines, imines , and nitriles , among which HCN and C 2 H 5 N are the main nitrogen-containing intermediates. Based on the experimental results, a detailed chemical kinetic model for describing the thermal decomposition of TMEDA was updated to improve predictions. The updated model can satisfactorily predict the consumption of TMEDA and the generation of most intermediates. Furthermore, detailed experimental measurements combined with kinetic analysis are used to clarify the decomposition reaction pathways of TMEDA. The rate of production (ROP) analysis indicates that unimolecular C-C bond dissociation is one of the leading consumption pathways of TMEDA, forming the (CH 3 ) 2 NCH 2 radical. In addition, the H-atom abstraction reactions involving CH 3 radicals formed by the C-N bond dissociation of (CH 3 ) 2 NCH 2 radicals further promote the consumption of TMEDA. Sensitivity analysis highlights that the unimolecular C-C bond dissociation reaction of TMEDA and the reactions involving CH 3 radicals mainly control the pyrolysis behavior of TMEDA. The detailed experimental results and kinetic analysis in this work are expected to contribute valuable references to further research on the combustion mechanism of TMEDA.