6533b838fe1ef96bd12a3b90

RESEARCH PRODUCT

Rheological Consequences of Hydrogen Bonding: Linear Viscoelastic Response of Linear Polyglycerol and Its Permethylated Analogues as a General Model for Hydroxyl-Functional Polymers

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Viscoelastic properties of linear, hydroxyl-functional polymers are only little understood with respect to the effect of functional group interactions. Melt rheology and thermal phase transitions of linear polyethers (polyglycerol, linPG-OH) and their methylated analogues (linPG-OMe) in a broad molecular weight range (Mn = 1–100 kg/mol) with low polydispersities (PDI) have been investigated as a general model for hydroxyl-functional polymers with respect to their functionality and hydrogen bond interactions. We provide detailed insight into the rheodynamics of nonentangled and well-entangled polyethers bearing one functional group per monomer unit. Booij–Palmen plots (BBP) revealed failure of the time–temperature superposition principle (TTS) for both types of polymers in the segmental relaxation region, while TTS holds in the terminal relaxation region. The characteristic modulus of linPG-OMe derived from the BBP clearly reflects the transition from the nonentangled to the fully entangled state with incr...