Berlin 2008 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 7: POSTERS Rheology
CPP 7.25: Poster
Montag, 25. Februar 2008, 16:45–19:00, Poster A
Statistics and dynamics of blends of linear and ring polymers. — •Michael Lang1,2 and Michael Rubinstein2 — 1Leibniz-Institute for polymer Research, Hohe Str. 6, 01069 Dresden, Germany — 2Department of Chemistry, University of North Carolina, 27599 Chapel Hill, N.C., USA
This work focuses on conformations and dynamics of blends of linear and ring polymers.
Rings in a melt of homo-polymer rings are compressed due to topology, if rings are significantly larger than the entanglement length. Dilute rings with degree of polymerization, Nr, immersed in a melt of linear polymers with degree of polymerization, Nl are almost ideal if Nl > Nr1/2 and swell if Nl < Nr1/2.
Dynamics of pure ring melts is enhanced as compared to pure linear melts. Thus, minority of linear chains immersed in ring melt experiences enhancement of diffusion and relaxation. On the other hand, minority of long entangled rings immersed in melt of long entangled linear chains gets temporarily trapped. This leads to a clear reduction in diffusion coefficient while keeping relaxation (as determined by half ring relaxation) almost unaffected.