Under linear temperature increase condition the thermal behaviour, mechanism and kinetic parameters of the exothermic first-stage decomposition reaction of the title compound have been studied by means of DSC, TG-DTG and IR. The reaction mechanism could be expressed by the following [GRAPHIC] The apparent activation energy, pre-exponential constant and reaction order of this reaction are 203.1 kJ mol(-1), 10(19.9) s(-1) and 0, respectively. The critical temperature of thermal explosion of the compound is 191.4 degreesC. The values of DeltaS(not equal) DeltaH(not equal) and DeltaG(not equal) of this reaction are 132.5 J mol(-1), 199.09 and 138.74 kJ mol(-1), respectively.