Europhys. Lett., 64 (3) , pp. 358-363 (2003)
Secondary relaxation in confined and bulk propylene carbonateC. Svanberg, R. Bergman and P. Jacobsson
Department of Applied Physics, Chalmers University of Technology SE-412 96 Göteborg, Sweden
(Received 7 April 2003; accepted in final form 27 August 2003)
Dielectric loss spectra of propylene carbonate in bulk and dissolved in a polymer matrix are investigated with focus on the currently debated excess wing. The spatial restrictions caused by the polymer matrix slow down the main structural ( ) relaxation, while the excess wing continuously transforms towards a shoulder with increasing spatial restrictions. We show that the excess wing in a consistent manner can be described by a secondary relaxation with only a weak dependence of the concentration of polymer. Thus the results imply that the excess wing is due to a secondary relaxation submerged in the -relaxation.
64.70.Pf - Glass transitions.
77.22.Gm - Dielectric loss and relaxation.
© EDP Sciences 2003