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CPP: Chemische Physik und Polymerphysik
CPP 32: Polymer dynamics
CPP 32.4: Vortrag
Mittwoch, 9. März 2005, 12:00–12:15, TU C130
Molecular dynamics in semifluorinated side-chain Polyesters as studied by Broadband Dielectric Spectroscopy — •Julius Tsuwi1, Lutz Hartmann1, Liane Häußler2, Dieter Jehnichen2, Doris Pospiech2, and Friedrich Kremer1 — 1Institute for Experimental Physics I, University of Leipzig,Linné Straße 5, 04103 Leipzig, Germany — 2Leibniz-Institute of Polymer Research Dresden, Hohe Straße 6, 01069 Dresden, Germany
The molecular dynamics in fluorinated side-chain (SC) polyesters was studied using Broadband Dielectric Spectroscopy (0.1Hz to 10MHz) at temperatures from 120 K to 500 K. It is observed that the fluorinated SC exhibits γ and δ-like relaxations. The γ process is assigned to librational fluctuations at the terminal position of the SC while the δ-like process reflects a cooperative motion of the SC as a whole. Two more processes, which are associated with main chain motion, are observed: A β process assigned to fluctuations of the carbonyl groups together with the phenyl ring and an α relaxation being the glass transition process. With respect to the flexibility of the main chain based on the analysis of the activation plot, it is concluded that a flexible main chain exhibits faster mobility in direct contrast to its side chain motion. On the other hand, the less flexible backbone show the reverse trend. The dielectric results are supported by DSC and temperature dependent SAXS. References [1] Gottwald A, et.al (2002) Macromol.Chem.Phys.203: 854[2] Tsuwi J, et.al(2004); Macromolecules 37:6050 [3]Tsuwi J, et.al;Coll.Poly.Sci.(subm.)[4] Tsuwi J,et.al;J.Poly.Sci.B (in prep.)