Fast relaxation in amorphous polymers: Relation to free volume
Universität Bayreuth, Physikalisches Institut,
95440 Bayreuth, Germany
2 Laboratoire de Physico-Chimie des Matériaux Luminescents, Université Lyon I, URA No 442 du CNRS, 43 boulevard du 11 Novembre 1918, Bât. 205, 69622 Villeurbanne Cedex, France
Accepted: 12 September 1997
A model of the fast relaxation process in amorphous polymers is presented based on the damping of the boson peak vibrations by the free-volume fluctuations. Comparison of the fast relaxation in polycarbonate as is seen in the low-frequency Raman spectra with the positron annihilation lifetime spectroscopy data for the fractional free volume in a broad temperature interval 50–450 K shows an apparent correlation between the relaxation strength and the free volume, in good agreement with the predictions of the model.
PACS: 64.70.Pf – Glass transitions / 63.20.Pw – Localized modes
© EDP Sciences, 1997