Non-gaussian effects in the cage dynamics of polymers

Abstract

The correlation between the fast cage dynamics and structural relaxation is investigated in a model polymer system. It is shown that the cage vibration amplitude, as expressed by the Debye-Waller factor, and the relaxation time ${\tau }_{\alpha }$ collapse on a single universal curve with a simple analytic form when the temperature, the density, the chain length and the monomer-monomer interaction potential are changed. For the physical states with the same ${\tau }_{\alpha }$ coincidence of the mean-square displacement, the intermediate scattering function and the non-Gaussian parameter is observed in a wide time window spanning from the ballistic regime to the onset of the Rouse dynamics driven by the chain connectivity. The role of the non-Gaussian effects is discussed.

8 pages, 5 figures

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Cited by in corpus (5)

• Universal divergenceless scaling between structural relaxation and caged dynamics in glass-forming systems
• Johari-Goldstein heterogeneous dynamics in a model polymer
• Fast Vibrational Modes and Slow Heterogeneous Dynamics in Polymers and Viscous Liquids
• Cage effect in supercooled molecular liquids: local anisotropies and collective solid-like response
• Weak links between fast mobility and local structure in molecular and atomic liquids