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Molecular dynamics in semifluorinated‐side‐chain polysulfone studied by broadband dielectric spectroscopy
Author(s) -
Tsuwi Julius,
Pospiech Doris,
Jehnichen Dieter,
Häußler Liane,
Kremer Friedrich
Publication year - 2007
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.26045
Subject(s) - polysulfone , side chain , relaxation (psychology) , dielectric , glass transition , polymer , materials science , pendant group , polymer chemistry , differential scanning calorimetry , activation energy , chemical physics , chemistry , thermodynamics , composite material , physics , optoelectronics , psychology , social psychology
The molecular dynamics of a set of polysulfone polymers have been studied with broadband dielectric spectroscopy. The materials comprise main‐chain polysulfones attached to semifluorinated (SF) oxydecylperfluorodecyl side chains. Through the analysis of the dielectric data together with information from differential scanning calorimetry and small‐angle X‐ray scattering, it can be shown that the oxydecylperfluorodecyl side chains are microphase‐separated and form nanodomains with an independent dynamic glass‐transition (δ SF ) relaxation. In addition to the α process (which is the glass transition of the main chain), other relaxation processes can be detected with Arrhenius‐type activation energies of 38–90 ± 2 kJ/mol. A γ SF process, observed only in polysulfone with SF side chains, can be assigned to librational fluctuations of the perpendicular component of the fluoroalkyl group. A γ B relaxation reflects fluctuations of the dipole moments (OSO and CO) of the polymer, whereas a β process, with high activation energies (>70 ± 2 kJ/mol), is assigned to packaging defects in the material. A detailed description of the processes is provided together with a proposed relaxation scheme. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 201–207, 2007