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Kinetics of Thermal Polymerization Can Be Studied during Continuous Cooling
Author(s) -
Liavitskaya Tatsiana,
Vyazovkin Sergey
Publication year - 2018
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.201700624
Subject(s) - kinetics , polymerization , thermal , materials science , thermodynamics , polymer chemistry , chemical engineering , polymer science , polymer , composite material , physics , quantum mechanics , engineering
It is demonstrated that differential scanning calorimetry can measure the kinetics of the thermally initiated polymerization during continuous cooling. The measurements are accomplished by switching from fast heating to much slower cooling. The study is exemplified by crosslinking polymerization (curing) of diglycidyl ether of bisphenol A epoxy and m ‐phenylenediamine taken in stoichiometric and nonstoichiometric ratios and measured under heating and cooling conditions. An advanced isoconversional method reveals that the reaction in the nonstoichiometric system follows the kinetics of the single‐step type. Its activation energy is constant and the same for heating and cooling conditions. The stoichiometric system exhibits the multistep kinetics characterized by the dependencies of the activation energy on temperature that differ qualitatively for cooling and heating runs. The discovered differences emphasize the need for further systematic studies of the thermal polymerization during continuous cooling.