Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (10): 2095-2100.doi: 10.3866/PKU.WHXB201307122

• THERMALANALYSIS KINETICS ANDTHERMOKINETICS • Previous Articles     Next Articles

Thermal Decomposition Characteristic and Kinetics of AIBN in Aniline Solvent

PENG Min-Jun, LU Gui-Bin, CHEN Wang-Hua, CHEN Li-Ping, LÜ Jia-Yu   

  1. Department of Safety Engineering, Institute of Chemical Technology, Nanjing University of Technology and Science, Nanjing 210094, P. R. China
  • Received:2013-06-03 Revised:2013-07-09 Published:2013-09-26
  • Contact: CHEN Wang-Hua E-mail:chenwh_nust@163.com
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51204099).

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Abstract:

2,2-Azobisisobutyronitrile (AIBN) is a typical material that shows overlap between endothermic phase change and exothermic decomposition. This phenomenon went against the kinetics of AIBN. To properly analyze the effect of endothermic phase change on the exothermic decomposition process and determine the non-isothermal behavior of AIBN in a solvent, a solution of AIBN (22.18% mass fraction) in aniline was tested under dynamic conditions by differential scanning calorimeter (DSC). Depending on heating rates, the onset temperature range of AIBN in aniline was from 79.90 to 94.47 ℃, and the decomposition enthalpy was 291 J·g-1 greater than that in its pure state, which could be regarded as phase change enthalpy. Based on the Kissinger method, the differences of the activation energy E and the frequency factor A of AIBN and its solution were quite small. The thermal decomposition processes of AIBN and its solution were analyzed by the Friedman method, which showed that the reaction progress range was less than 0.20, in which the endothermic phase change of solid AIBN would disturb its exothermic decomposition. When α was greater than 0.20, the dependence of E(α) and ln(A(α)·f(α)) on α were roughly the same. These results show that aniline is an inertial solvent; that is, decomposition of AIBN is not disturbed by aniline. This means that the decomposition mechanism of AIBN in aniline could be regarded as the same as that in its solid state. The decomposition kinetics of AIBN could be described according to the Mampel power law, G(α)=α3/2, which is based on the Friedman and Coats-Redfern integral methods, and the average apparent activation energy was 139.93 kJ·mol-1.

Key words: 2,2-Azobisisobutyronitrile, Thermal decomposition mechanism, Aniline, Inertial solvent, Differential scanning calorimeter

MSC2000: 

  • O641