Univerzita PardubiceFakulta chemicko- technologická

Univerzita Pardubice

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Publikace detail

How to determine activation energy of glass transition

Autoři: Svoboda Roman

Rok: 2014

Druh publikace: článek v odborném periodiku

Název zdroje: Journal of Thermal Analysis and Calorimetry

Název nakladatele: Springer

Strana od-do: 1721-1732

Tituly:

Jazyk	Název	Abstrakt	Klíčová slova
cze	Jak stanovit aktivační energii skelného přechodu	Článek kriticky hodnotí běžné metody stanovení zdánlivé aktivační energie strukturní relaxace. Na simulovaných datech je testována úspěšnost těchto metod.	skelný přechod; aktivační energie; TNM model; strukturní relaxace
eng	How to determine activation energy of glass transition	The article critically reviews the current methodologies for determination of apparent activation energy of structural relaxation, a dagger h, in the glass transition range. Tool-Narayanaswamy-Moynihan phenomenological model was used to simulate data for all major types of relaxation behavior, which were consequently evaluated in terms of the tested methodologies (curve-fitting, evaluation of a dagger h from intrinsic cycles and evaluation of a dagger h* from constant heating rate cycles). Advantages and disadvantages of particular methodologies are demonstrated and thoroughly discussed. In addition, effects of various data-distortive effects influencing determination of glass transition activation energy are demonstrated and described. The discussed data-distortive effects include presence thermal gradients, improperly designed temperature programs, incorrectly applied subtractions of the thermokinetic background, or inability of the DSC instrument to perform high cooling/heating rates. Detailed guide for correct determination of a dagger h* from DSC measurements is introduced.	Glass transition; Activation energy; TNM model; Structural relaxation