Regensburg 2016 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 57: Polymer Dynamics and Rheology (joint session CPP/DY, organized by CPP)
CPP 57.5: Vortrag
Donnerstag, 10. März 2016, 16:00–16:15, H40
Branch Point Motion in Asymmetric Star Polymers Investigated by Molecular Dynamics Simulations — •Stefan Holler1,2, Angel Moreno2, Michaela Zamponi1, and Dieter Richter1 — 1Forschungszentrum Jülich GmbH, 52425 Jülich, Germany — 2Centro de Fisica de Materiales, 20018 San Sebastian, Spain
Large-scale molecular dynamics simulations of three-arm asymmetric star polymers have been performed to study the motion of the branch point and the so-called hopping parameter p2 that characterizes the effective friction associated to the short side arm. The simulated star polymer systems consist of a large backbone (10 or 16 entanglements) and a central short unentangled side arm.
This work expands the investigation by Bacova et al. [1] in similar stars with entangled side arms. Surprisingly, the frictional contribution of the unentangled side arms on the motion of the linear backbone is much larger than assumed by theory. The value of p2 can be calculated from the simulation data using general assumptions that hold true for all versions of hierarchical relaxation models. The most consistent description of the simulation results suggests that p2 is not a constant but depends on architecture and molecular weight, and that hopping occurs in the bare, undilated tube.
[1] Bacova et al., Macromolecules 47 (2014) 3362