Open AccessIdentification of isothermal crystallization kinetics of poly(ether‐ketone‐ketone) based on spherulite growth measurements and enthalpic data
Author(s) -
Chelaghma Saber Ayoub,
De Almeida Olivier,
Margueres Philippe,
Passieux JeanCharles,
Perie JeanNoël,
Vinet Alain,
Reine Bénédicte
Publication year - 2020
Publication title -
polymer crystallization
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.443
H-Index - 9
ISSN - 2573-7619
DOI - 10.1002/pcr2.10141
Subject(s) - crystallization , nucleation , spherulite (polymer physics) , differential scanning calorimetry , optical microscope , materials science , polarized light microscopy , thermodynamics , crystal growth , isothermal process , kinetic energy , crystallography , chemistry , scanning electron microscope , optics , physics , composite material , quantum mechanics
Differential scanning calorimetry and polarized optical microscopy were used in this study to identify the contributions and interactions of both primary and secondary crystallization processes during the isothermal crystallization of a PEKK 70/30. Primary crystallization, which is related to the growth of spherulites, was monitored by polarized optical microscopy. The data collected allowed identifying the corresponding nucleation density and crystal growth rate that were subsequently used to feed a kinetic model derived from Hillier's equation and already been reported in literature. The DSC data were then used to determine the contribution of the secondary crystallization mechanism, considering that primary crystallization is related to the instantaneous nucleation and growth of spherulites. From these data, an inverse approach was used to identify the few remaining parameters of the model. The proposed approach has the advantage of providing kinetic parameters representative of the secondary crystallization mechanism that are not dependent on the inverse identification procedure. Doing so, a noninteger Avrami exponent equal to 2.7 is obtained and discussed.