Issue |
Europhys. Lett.
Volume 44, Number 1, October I 1998
|
|
---|---|---|
Page(s) | 37 - 43 | |
Section | Condensed matter: structure, thermal and mechanical properties | |
DOI | https://doi.org/10.1209/epl/i1998-00431-5 | |
Published online | 01 September 2002 |
Order-disorder transition in a poly(styrene-b-isoprene) diblock copolymer at hypersonic frequencies
1
Foundation for Research and Technology-Hellas (FORTH), Institute of Electronic Structure and Laser - P.O. Box 1527, 711 10 Heraklion Crete, Greece
2
Max-Planck Institut fur Polymerforschung - Postfach 3148, D-55021 Mainz, Germany
3
Department of Chemistry, University of Athens - Zografou 15771, Athens, Greece
Received:
9
March
1998
Accepted:
28
July
1998
The order-to-disorder transition (ODT) has been studied in a poly(styrene-b-isoprene) diblock copolymer with a polystyrene (PS) volume fraction fPS of 0.22 at hypersonic frequencies using a tandem Fabry-Perot interferometer. Because of the asymmetric composition we are effectively studying the sound dispersion in a composite material made of hard PS spheres embedded in a soft polyisoprene matrix. All measurements are made in the long-wavelength limit, qD<1, where q is the scattering wave vector and D is the sphere diameter. The transition temperature (TODT) was identified earlier with rheology and SAXS at . We have investigated the sound velocity and attenuation at temperatures below and above the transition. We find the signature of TODT from the broad hypersonic attenuation reflecting the enhanced segmental mobility due to mixing at temperatures near the .
PACS: 61.41.+e – Polymers, elastomers, and plastics / 78.35.+c – Brillouin and Rayleigh scattering; other light scattering / 64.60.Cn – Order-disorder transformations; statistical mechanics of model systems
© EDP Sciences, 1998
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.