Under linear temperature increase condition the thermal behavior, 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 was proposed. The kinetic model function in differential form, apparent activation energy and pre-exponential constant of this reaction are (1 - alpha)(0-5), 194.7 kJ mol(-1) and 10(18.45) s(-1), respectively. The critical temperature of thermal explosion of the compound is 200.8degreesC. The values of DeltaS(not equal) DeltaH(not equal) and DeltaG(not equal) of this reaction are 133.3 J mol(-1) K-1, 203.9 kJ mol(-1) and 142.0 kJ mol(-1), respectively. (C) 2003 Elsevier B.V. All rights reserved.