NONISOTHERMAL CRYSTALLIZATION KINETICS OF POLY(BETA-HYDROXYBUTYRATE)

Kinetics of nonisothermal crystallization of poly( beta-hydroxybutyrat e) from melt and glassy states were performed by differential scanning calorimetry under various heating and cooling rates. Several differen t analysis methods were used to describe the process of nonisothermal crystallization. The results showed that both Avrami treatment and a n ew method developed by combining the Avrami equation and Ozawa equatio n could describe this system very well. However, Ozawa analysis failed . By using an evaluation method, proposed by Kissinger, activation ene rgies have been evaluated to be 92.6 kJ/mol and 64.6 kJ/mol for crysta llization from the glassy and melt state, respectively. (C) 1998 John Wiley & Sons, Inc.