title: 13C solid state NMR investigation of structural relaxation of the polymer backbone in poly (ethylmethacrylate).
abstract: Geometry and time scale of structural relaxation of poly(n-alkylmethacrylates) above the glass transition is studied by temperature dependent one- and two-dimensional 13C-NMR spectroscopy. The geometry of the isotropization of the polymer backbone as deduced from detailed analysis of spectral line shapes is identified as random angular jumps. Analysis of echo decays confirms that at a given temperature this isotropization can adequately be described with a single correlation time. The results are discussed in terms of conformational memory and local structure recently identified in these polymeric glasses.
authors.affiliation: Max-Planck-Institut für Polymerforschung, Postfach 3148, 55021 Mainz, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Wind
authors.forename: Lothar
authors.initials: L
authors.lastname: Brombacher
authors.forename: Andreas
authors.initials: A
authors.lastname: Heuer
authors.forename: Robert
authors.initials: R
authors.lastname: Graf
authors.forename: Hans Wolfgang
authors.initials: HW
authors.lastname: Spiess
mesh_terms: D002247:Carbon Isotopes; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008768:Methylmethacrylates / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D008768:Methylmethacrylates; C009931:poly(ethylmethacrylate)