title: Entanglement transition in hyperbranched polyether-polyols.
abstract: Are hyperbranched polymers capable of forming entanglements? This is the central issue of this contribution. Hyperbranched polyglycerol (hbPG) samples with different molecular weights (600-106 000 g · mol(-1) ), narrow polydispersities (1.2-1.8) and high degrees of branching (≈0.6) were prepared by anionic ring-opening polymerization. The viscoelastic properties of these polymers with respect to molecular architecture and molar mass were investigated. At low molecular weights "classical" scaling behavior between zero shear viscosity and molecular weight can be observed, whereas between 3 000 and 10 000 g · mol(-1) a plateau-like area is found. The results indicate entanglement dynamics when exceeding a critical molar mass ($\overline {M} _{{\rm c}}^{*} $ ≈ 20 000 g · mol(-1) ) due to entangled hyperbranched polyglycerols.
authors.affiliation: Institute of Organic Chemistry, Organic and Macromolecular Chemistry, Duesbergweg 10-14, Johannes Gutenberg-University Mainz, D-55099 Mainz, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Tonhauser
authors.forename: Daniel
authors.initials: D
authors.lastname: Wilms
authors.forename: Yasmin
authors.initials: Y
authors.lastname: Korth
authors.forename: Holger
authors.initials: H
authors.lastname: Frey
authors.forename: Christian
authors.initials: C
authors.lastname: Friedrich