INITIAL SHOCK-TUBE STUDIES OF MONOMETHYLAMINE

The decomposition of dilute mixtures of monomethylamine (MMA) in argon were studied in the reflected wave of a shock tube. Kinetic measurements of both the decomposition of MMA and the formation of ammonia, one of the postulated reaction products, were made by use of infrared (IR) emission techniques. The decomposition was studied over the temperature range 1275-2400 K and the total pressure range 1-10 atm. Both MMA decomposition and ammonia formation were found to obey the Hinshelwood-Lindemann model for a unimolecular reaction. Arrhenius parameters were obtained over the experimental temperature and pressure ranges and the extrapolated parameters for high and low pressure limits were obtained. In the high pressure limit Ea = 48.15 kcal/mol and log A = 10.84. At low pressure Ea = 35.14 kcal/mol and log A = 13.50. Various reasonable mechanisms are discussed for the decomposition and evidence is offered to indicate that the predominant mechanism is C-N bond scissure followed by a short free-radical reaction sequence. © 1979 American Chemical Society.