Determination of kinetic parameters for thermal decomposition of polymerization initiators by differential scanning calorimetry

The kinetic and thermal parameters for the decomposition of a group of polymerization initiators were determined using differential scanning calorimetry (DSC). The solvent was di‐n‐butylphthalate, and the measurements were made in the temperature range between 50°C and 180°C. The activation energies for azobisisobutyronitrile and benzoyl peroxide are 137.5 kJ/mol (32.9 kcal/mol) and 119.6 kJ/mol (28.6 kcal/mol), respectively, which is in agreement with literature values. The activation energies for technical lauroyl peroxide and technical methylethylketone peroxide are 141.7 kJ/mol (33.9 kcal/mol) and 181.4 kJ/mol (43.4 kcal/mol), respectively, and are higher than the values reported in the literature. This is probably due to the fact that technical samples were used. The heats of decomposition were also obtained. They are − 230.7 kJ/mol ( − 55.2 kcal/mol) for azobisisobutyronitrile, − 293.0 kJ/mol ( − 70.1 kcal/mol) for benzoyl peroxide, − 693.5 J/g ( − 165.9 cal/g) for lauroyl peroxide, and −459.8 J/g ( − 110.0 cal/g) for methylethylketone peroxide.