Abstract
The spherulite growth, nucleation-related,K g, parameter values obtained from isothermal data (by DSC or optical microscopy) and two other adjustable parameters (the spherulite growth rate preexponential factor and the Avrami's or Tobin's exponent,n) have been used with Nakamura's and Tobin's modified non-isothermal equations to model the kinetics of polymer non-isothermal crystallization. Malkin's model was also tested, for comparison.
It is shown that, for polymers that crystallize on cooling almost entirely at temperatures higher than the maximum growth rate temperature, this Tobin's-like non-isothermal model accurately describes the experimental behaviour with only 2 parameters.
Zusammenfassung
Zur Modellierung der Reaktionskinetik der nichtisothermen Polymerkristallisation wurden unter Anwendung der modifizierten nichtisothermen Gleichung von Nakamura und Tobin der SphärolithwachstumsparameterK g (ermittelt durch DSC oder optischer Mikroskopie aus den isothermen Daten) und zwei weitere Stellparameter (der präexponentielle Faktor der Sphärolithwachstumsgeschwindigkeit und der Avrami-oder Tobin-Exponentn) verwendet. Zum Vergleich wurde auch das Modell von Malkin getestet. Es wurde gezeigt, daß für Polymere, die beim Abkühlen fast vollständig kristallisieren, oberhalb der Temperatur für die maximale Wachstumsgeschwindigkeit das nichtisotherme Tobin-sche Modell das experimentelle Verhalten mit nur 2 Parametern exakt beschreibt.
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Martins, J.A., Cruz-Pinto, J.J.C. Prediction of poly(oxymethylene) non-isothermal crystallization behaviour from isothermal data. Journal of Thermal Analysis 40, 621–628 (1993). https://doi.org/10.1007/BF02546632
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DOI: https://doi.org/10.1007/BF02546632