Departments > Polymer Structures > Publications

Publications

Jehnichen, D. ; Pospiech, D. ; Häußler, L. ; Friedel, P. ; Gottwald, A. ; Kummer, S.
Self-Organization in Semifluorinated Polymers

Alkyl-perfluoroalkyl compounds are known to form a microphase-separated structure due to the thermodynamic immiscibility between the fluorinated and the protonated segments. Many similarities between bulk and surface structures of such polymers were found in the past which can be explained by both microphase separation in the bulk as well as surface segregation of the fluorinated parts. Basing on this concept, polymers with chemically different main chains were attached with alkylperfluoroalkyl side chains (particularly, oxydecylperfluorodecyl chains, -O-(CH2)10-(CF2)9-CF3. Combined investigations by means of temperature-dependent X-ray scattering, molecular modeling and DSC measurements were performed to characterize the bulk structure in dependence on the flexibility of the main chain as well as the density of side chains. The polymers under investigation show one or more phase transitions in the temperature range from room temperature to 300DGC which can be assigned as transitions between different smectic structures. These phases are characterized to have positive as well as negative expansion coefficients, respectively, indicating changes of the tilt angle of the side chains and/or the degree of interdigitation. The polymer melts feature a high memory behavior evidenced by reversed imaging of the scattering patterns in the heating and cooling runs

Source
Materials Science Forum 443-444

Pages
223-226

DOI
http://md1.csa.com/partners/viewrecord.php?requester=gs&collection=TRD&recid=200405A2P0430EP

Published
January 2004
 
Publications
Publikationen

Departments

Polymer Structures