Effects of gold catalyst on the thermal decomposition characteristics and thermal safety of methylhydrazine.

In the study, the effects of gold catalyst on the thermal decomposition characteristics and thermal safety of methylhydrazine were studied with the differential scanning calorimetry. The kinetic and thermal safety parameters of methylhydrazine with and without gold catalyst were calculated, including apparent activation energy, pre-exponential constant, self-accelerating decomposition temperature, critical temperatures of thermal explosion and adiabatic time to explosion. Thus, entropies of activation, enthalpies of activation and free energies of activation of thermodynamic parameters were also computed. The results showed that the thermal decomposition of methylhydrazine had only one strong exothermic process and the values of apparent activation energy, self-accelerating decomposition temperature and critical temperatures of thermal explosion of methylhydrazine were 159.13 kJ·mol−1, 451.53 K and 469.55 K, respectively. However, these parameters of methylhydrazine with the presence of gold catalyst were 69.03 kJ·mol−1, 361.24 K and 400.22 K, respectively. Non-isothermal kinetics analysis revealed that gold greatly reduced the values of apparent activation energy, self-accelerating decomposition temperature and critical temperatures of thermal explosion of methylhydrazine, leading to an obvious promoting effect on its thermal decomposition. Therefore, gold would significantly decrease the thermal safety of methylhydrazine and increase its explosion risk in a closed system. [ABSTRACT FROM AUTHOR]