Material Behaviour Isothermal and nonisothermal crystallization kinetics of elastomeric polypropylene

This article studies the crystallization behavior of elastomeric polypropylene, a new type of polypropylene, under isothermal and nonisothermal conditions from the melt by differential scanning calorimetry. During isothermal crys- tallization, the development of relative crystallinity with the crystallization time is analyzed by the Avrami equation with the exponent n=2.0. For nonisothermal studies, the Ozawa theory is employed, and the result is found that the Ozawa approach can adequately describe the nonisothermal crystallization process. In addition, the treatment by combin- ing the Avrami and Ozawa equation is employed to describe the nonisothermal crystallization process as well. The kinetic parameter F(T) with specific physical meaning is determined. The calculated activation energies are 163 kJ/mol for isothermal crystallization by the Arrhenius relation and 154 kJ/mol for nonisothermal crystallization by the Kissinger method.  2002 Elsevier Science Ltd. All rights reserved.