Europhys. Lett.
Volume 64, Number 3, November 2003
Page(s) 358 - 363
Section Condensed matter: structure, mechanical and thermal properties
Published online 01 November 2003
DOI: 10.1209/epl/i2003-00202-4
Europhys. Lett., 64 (3) , pp. 358-363 (2003)

Secondary relaxation in confined and bulk propylene carbonate

C. 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 ( $\alpha$) 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 $\alpha$-relaxation.

64.70.Pf - Glass transitions.
77.22.Gm - Dielectric loss and relaxation.

© EDP Sciences 2003