Stress Relaxation In Entangled Polymer Melts

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Download Free PDFStress Relaxation in Entangled Polymer MeltsRalf EveraersJi-Xuan Hou

2010, Physical Review Letters

https://doi.org/10.1103/PHYSREVLETT.105.068301visibility

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Abstract

We present an extensive set of simulation results for the stress relaxation in equilibrium and stepstrained bead-spring polymer melts. The data allow us to explore the chain dynamics and the shear relaxation modulus, G(t), into the plateau regime for chains with Z = 40 entanglements and into the terminal relaxation regime for Z = 10. Using the known (Rouse) mobility of unentangled chains and the melt entanglement length determined via the primitive path analysis of the microscopic topological state of our systems, we have performed parameter-free tests of several different tube models. We find excellent agreement for the Likhtman-McLeish theory using the double reptation approximation for constraint release, if we remove the contribution of high-frequency modes to contour length fluctuations of the primitive chain. PACS numbers: 83.80.Sg (Polymer melts), 83.10.Rs (MD simulation rheology), 61.25.he (liquid structure polymer melt)

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