J. Phys. II France
Volume 7, Numéro 11, November 1997
Page(s) 1635 - 1650
DOI: 10.1051/jp2:1997207
J. Phys. II France 7 (1997) 1635-1650

Study of the $\mathsf{\alpha}$-Mechanical Relaxation in Molecular Glass-Forming Liquids

A. Faivre, L. David and J. Perez

Groupe d'Études de Métallurgie Physique et de Physique des Matériaux UMR CNRS 5510, Bâtiment 502, Institut National des Sciences Appliquées de Lyon, 20 avenue A. Einstein, 69621 Villeurbanne Cedex, France

(Received 7 March 1997, received in final form 20 July 1997, accepted 18 July 1997)

A procedure yielding to the determination of the low-frequency dynamical behavior of glass-forming systems with low glass transition temperature is presented in this paper. The liquids are injected in an inorganic porous medium and the mechanical response of the heterogeneous composite samples is studied. It is shown that the dynamic behavior of the liquid is poorly affected by the presence of the substrate. This enables to build the long-time relaxation diagram for maltitol, sorbitol and LiCl, 6H 2O. The mechanical measurements are interpreted in the framework of a model based on the assumptions of localized disorder (defects) and hierarchically constrained dynamics in the glass transition region.

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