Estimation of activation energies for structural relaxation and viscous flow from DTA and DSC experiments

Autor:	Masahiro Tatsumisago, C.T. Moynihan, Tsutomu Minami, S.-K. Lee
Rok vydání:	1996
Předmět:	Viscosity Differential scanning calorimetry Yield (engineering) Chemistry Differential thermal analysis Enthalpy Relaxation (physics) Thermodynamics Activation energy Physical and Theoretical Chemistry Condensed Matter Physics Glass transition Instrumentation
Zdroj:	Thermochimica Acta. :153-162
ISSN:	0040-6031
Popis:	The activation energy ΔH∗ for structural relaxation in the glass transition region can be determined from the heating rate dependence of the glass transition temperature Tg or the cooling rate dependence of the limiting fictive temperature T′f measured using DSC or DTA. ΔH∗ values determined this way are in good agreement with the shear viscosity activation energies ΔH∗η. ΔH∗η for high Tg inorganic glasses can also be estimated from the width Δ(1Tg) of the glass transition region measured by DSC or DTA using an empirical constant C = (ΔH∗ηR)Δ(1Tg). New data for sodium borate glasses yield values of the constant C in agreement with those from earlier studies.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::bcce14e1668be8074a7c087a72906c5b https://doi.org/10.1016/0040-6031(95)02781-5 Zobrazit plný text záznamu Full Text from ScienceDirect