Simple-liquid dynamics emerging in the mechanical shear spectra of poly(propylene glycol)

Catalin Gainaru, Tina Hecksher, Fei Fan, Kunyue Xing, Burak Cetinkaya, Niels Boye Olsen, Jeppe C. Dyre, Alexei Sokolov, Roland Böhmer

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The present dielectric investigations of methyl-terminated poly(propylene glycol) (PPG) oligomers reveal that near the glass transition the normal modes and segmental relaxation merge in a single-process susceptibility spectrum, similar to previous observations on OH-terminated species. Moreover, the present shear-mechanical measurements demonstrate that the vanishing of chain modes can be monitored without recourse to dielectric investigations, which are able to access chain dynamics only for the relatively small fraction of type A polymers. As the normal and segmental modes merge, the viscosity displays a crossover from a polymer-like regime governed by the chain dynamics, to a simple-liquid regime governed by the structural relaxation.
TidsskriftColloid and Polymer Science
Udgave nummer12
Sider (fra-til)2433-2437
Antal sider5
StatusUdgivet - 18 okt. 2017


  • Dielectric spectroscopy
  • Rheology
  • Normal modes
  • Hydrogen bonding

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