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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 24: Poster Session I

CPP 24.51: Poster

Montag, 16. März 2020, 17:30–19:30, P3

RheoNSE for the study of topological interactions in polymers — •Max Wolff — Department for Physics and Astronomy, Uppsala University

Entangled polymers show unique flow behaviors, since the relaxation processes occur on time scales relevant for our daily lives, ranging from milliseconds to hours or even days. Yet, due to experimental limitations, the nonlinear rheological behavior of complex fluids is only modestly understood. We investigate the microscopic structure and dynamics of highly entangled polymers under shear with small angle neutron scattering (SANS) and neutron spin echo (NSE), respectively.

The viscoelastic properties of materials are typically investigated by rheology. If such measurements are done in shear rate controlled mode, the formation of a stress plateau can be observed above a critical shear rate. It is known that for these systems the measured stress shows a plateau when investigated under controlled shear rate. At these shear rates the polymer might disentangle resulting in a change in the topological interactions between the chains. This transition can only be observed in the dynamics of the chains studied with NSE.