Kinetic analysis of solids of the quasi-autocatalytic decomposition type: SADT determination of low-temperature polymorph of AIBN

Simulations of SADT values based on the heat balance of the system are presented for azobisisobutyronitrile (AIBN). These simulations used kinetic parameters obtained from heat flow calorimetry experiments performed at temperatures in the stability range of low-temperature (L-T) polymorph of AIBN. Thermal Activity Monitor (TAM) data were collected in the range of 55-70 degrees C. The simulated SADT value for L-T AIBN amounts to 46 degrees C. This is very similar to the computed results obtained in the RAM project (Malow et al., 2015; Roduit et al., 2015; Moukhina, 2015; Kossoy et al., 2015) for the high-temperature (H-T) form of AIBN which amounts to 47 degrees C and is also in full agreement with the large scale experimentally found SADT of AIBN (47 degrees C) (Malow et al., 2015). The prerequisites for collecting proper kinetic data for the quasi-AC type energetic materials in which the phase change phenomena (polymorphic transformation or melting) precedes the decomposition are discussed. The apparent paradox when the application of incorrect kinetics applied in narrow a or T ranges may sometimes result in the correct predictions of such safety parameters, such as SADT, is also explained.