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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 17: Poster: Polymer Networks and Dynamics

CPP 17.6: Poster

Montag, 20. März 2017, 18:30–21:00, P1C

Topological interactions in polymers under shear — Maciej Kawecki¹, Franz Adlmann¹, Philipp Gutfreund², Sudipta Gupta³, Peter Falus², David Uhrig³, and •Max Wolff¹ — ¹Department for Physics and Astronomy, Uppsala Univeristy, Sweden — ²Institut Laue-Langevin, Grenoble, France — ³Oak Ridge National Laboratory, Oak Ridge, TN, USA

Since decades topological interactions as described by the reptation theory of DeGennes, Doi and Edwards are among the most successful concepts in physics. The scaling laws and viscoelastic properties in polymers are predicted correctly. However, currently no such generalized theory is available for large deformations, where shear thinning occurs. Even more, until now, no experimental approach allowed to test possible extensions of the reptation theory, such as convective constrain release, which would have the potential to theoretically predict the shear thinning transition. We present a neutron spin echo based method to directly measure and quantify nanoscale dynamics in flowing liquids and we extract the chain dynamics in a polymeric melt beyond the shear thinning transition. Under flow we find an additional relaxation process, which we attribute to shear thinning and which is in line with the theory of convective constrain release.