Dresden 2014 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 28: (Hydro) Gels and Elastomers

CPP 28.2: Vortrag

Mittwoch, 2. April 2014, 10:00–10:15, ZEU 222

Nonlinear rheology and self-healing kinetics of supramolecular polymer network — •Tingzi Yan¹, Klaus Schröter¹, Florian Herbst², Wolfgang Binder², and Thomas Thurn-Albrecht¹ — ¹Institute of Physics, Martin-Luther University Halle-Wittenberg, Halle 06120, Germany — ²Institute of Chemistry, Martin-Luther University Halle-Wittenberg, Halle 06120, Germany

A series of supramolecular polyisobutylenes melt samples showing self-healing properties was investigated by small angle x-ray scattering and rheological experiments in order to get a microscopic understanding of special mechanical properties. All samples were end functionalized with barbituric acids groups but had different molecular weights. Analysis of the SAXS data and linear rheology showed that the samples form a reversible network of interconnected micelles in which barbituric acids clusters act as physical cross-linking points. Startup shear experiments with large shear strain and high shear rate led to shear yielding accompanied by a fast stress relaxation, indicating failure of the cross-linked network. Small amplitude oscillatory shear measurements after shear yielding were performed to measure the recovery of network. Based on the results, we propose a two-step model for the self-healing process.