Kinetics and mechanism of the thermal decomposition of monomethylhydrazine by accelerating rate calorimetry

Abstract

The thermal decomposition reaction of monomethylhydrazine was studied using an accelerating rate calorimeter. Nitrogen, ammonia, methylamine, methane and ethane were the major products. Dimethylamine, 1,2-dimethyldiazene and traces of nine other nitrogenous compounds or hydrocarbons were observed in the product mixture. The Arrhenius parameters for the decomposition reaction are compensated and linearly related by the relationship In A = E a/Rθ + ln k o, with a compensation temperature θ of 478 K. The isokinetic temperature is 475 K. Activation energies were found to be in the range 71.8–114.8 kJ mol −1. A mechanism involving surface-bound amido, imido, nitrido, hydrido, methylene and methyl species is proposed to account for the major and minor products.