Probing the surface Tg of monodisperse PS by local thermal analysis
article
The surfaces of compression-molded PS samples with different Mw (9.85 kg/mol-502 kg/mol) and narrow molecular weight distributions were examined using an AFM equipped with a thermal probe in the local thermal analysis (LTA) mode to get further insight into possible explanations of a decrease in glass transition temperature (Tg) at polymer surfaces. No difference in Tg, at the very surfaces could be detected for these samples. Instead, different molecular weights contribute to differences in the micro-thermomechanical behavior. Acareful analysis hints to possibilities to use this analytic method for the determination of M w and/or molecular weight distribution on polymeric surfaces. Furthermore, hints to a disentanglement of macromolecules with molecular weights lower than the critical molecular weight to form a random coil, initiated by the indentation with the thermal probe during the LTA experiment, are found.
Topics
Compression moldingEllipsometryGlass transitionMacromoleculesMolecular weightPolymethyl methacrylatesSecondary ion mass spectrometrySuperconducting transition temperatureSurface phenomenaThermoanalysisViscosityCapillary wavesLocal thermal analysis (LTA)Motion dynamicsPolymer surfacesScanning thermal microscopyPolystyrenes
TNO Identifier
238342
ISSN
00249297
Source
Macromolecules, 38(3), pp. 844-850.
Publisher
Wiley
Pages
844-850
Files
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