Crystallization Behavior of a Novel Ether Ketone Polymer Containing Meta-phenylene Linkage: PEKEKK (T/I)

Abstract

Nonisothermal and isothermal melt crystallization kinetics of a novel aryl ether ketone polymer containing meta-phenylene linkages, PEKEKK (T/I), were studied by differential scanning calorimetry (DSC). The Avrami equation modified by Jeziorny and a new approach by combining the Avrami equation with the Ozawa equation could describe the nonisothermal crystallization. Isothermal crystallization could also be described by the Avrami equation. The activation energies were 187 and 159 kJ/mol for nonisothermal and isothermal crystallization, respectively. Using the Hoffman-Weeks method, the equilibrium melting point T _m ^o was estimated as 353°C. From the spherulitic growth equation proposed by Hoffman and Lauritzen, the nucleation parameter K _g of the isothermal melt crystallization was estimated as 5.49 × 10⁵ K². The crystallization characteristics of PEKEKK (T/I) were compared with those of all-para PEKEKK. The differences were explained by differences in the chain flexibility of the two polymers.

Keywords:

• Avrami equation
• Crystallization kinetics
• DSC
• PEKEKK (T/I)

ACKNOWLEDGMENTS

This research was supported by the National Natural Science Foundation of China and the Chinese “863” high-technology funds. We also express warm thanks to Dr. P. Geil of the University of Illinois for his good advice and critical comments on this paper.