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RESEARCH PRODUCT
Can Hyperbranched Polymers Entangle? Effect of Hydrogen Bonding on Entanglement Transition and Thermorheological Properties of Hyperbranched Polyglycerol Melts
Christian FriedrichMartina SchömerChristoph TonhauserCarina OsterwinterChristian SchubertChristian SchubertDaniel WilmsHolger Freysubject
Phase transitionMaterials sciencePolymers and PlasticsHydrogen bondOrganic ChemistryThermodynamics02 engineering and technology010402 general chemistry021001 nanoscience & nanotechnology01 natural sciencesViscoelasticity0104 chemical sciencesInorganic ChemistryEnd-groupRheologyPolymer chemistryMaterials ChemistryMolecule0210 nano-technologyTopology (chemistry)Macromoleculedescription
Melt rheology and thermal phase transition of a series of hyperbranched polyglycerol samples (hbPG) (DB ≈ 60%) in a broad molecular weight range (Mn = 600–440 000 g/mol) were investigated and correlated to both molecular weight and nature of the end group (hydroxyl vs permethylated and trimethylsilylated). The well-characterized and defined flexible polyethers are particularly suitable to shed light on the linear viscoelastic behavior with respect to (i) hyperbranched topology and (ii) hydrogen bond interactions, particularly in comparison to the perfectly linear polyglycerol counterparts studied recently [Osterwinter, C.; Macromolecules 2015, 48, 119−130]. We present a detailed examination of differences found in the characteristic moduli as a consequence of functionality and topology leading to an estimation of both a stickiness parameter H and a connectivity parameter B of hyperbranched molecules. The appearance of a plateau region of the dynamic moduli indicates entanglement behavior, although the det...
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-11-04 | Macromolecules |