2002 -07 -03
10 :15 at ML J 21

Experimental confrontation of reptation models for fast flows

Jan van Meerveld

Institute of Polymers, ETH Zurich

Different reptation models for fast flows are confronted against experimental results for uniaxial flows and shear flows. Confrontation of this models for uniaxial flows reveals that the usually considered relationship between reptation and Rouse time is unjustified. Furthermore it is observed that different model show roughly an identical behavior for identical model parameters. For start-up of shear flows an overshoot in the first normal stress difference is observed associated to chain stretching and the performance of the different models varies strongly. Finally the influence of tube length fluctuations is discussed and some initial results are shown.