title: Polymer chain dynamics in a random environment: heterogeneous mobilities.
abstract: We present a neutron scattering investigation on a miscible blend of two polymers with greatly different glass-transition temperatures Tg. Under such conditions, the nearly frozen high-Tg component imposes a random environment on the mobile chain. The results demand the consideration of a distribution of heterogeneous mobilities in the material and demonstrate that the larger scale dynamics of the fast component is not determined by the average local environment alone. This distribution of mobilities can be mapped quantitatively on the spectrum of local relaxation rates measured at high momentum transfers.
authors.affiliation: Institut für Festkörperforschung, Forschungszentrum Jülich, 52425 Jülich, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Niedzwiedz
authors.forename: A
authors.initials: A
authors.lastname: Wischnewski
authors.forename: M
authors.initials: M
authors.lastname: Monkenbusch
authors.forename: D
authors.initials: D
authors.lastname: Richter
authors.forename: A-C
authors.initials: AC
authors.lastname: Genix
authors.forename: A
authors.initials: A
authors.lastname: Arbe
authors.forename: J
authors.initials: J
authors.lastname: Colmenero
authors.forename: M
authors.initials: M
authors.lastname: Strauch
authors.forename: E
authors.initials: E
authors.lastname: Straube
mesh_terms: D045424:Complex Mixtures / Q000737:chemistry; D003198:Computer Simulation; D008956:Models, Chemical; D008958:Models, Molecular; D015233:Models, Statistical; D011092:Polyethylene Glycols / Q000737:chemistry*; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D013696:Temperature
chemical_list: D045424:Complex Mixtures; D011092:Polyethylene Glycols; D019904:Polymethyl Methacrylate