Experimental test of the bond lifetime renormalization model in telechelic associating polymers
ORAL
Abstract
Associating polymers with transient (dynamic) bonds demonstrate unique viscoelastic properties in comparison to the conventional polymers. The mechanisms controlling dynamics of associating polymers is rather complex and still not well understood. Transient bonds introduce additional relaxation times into the system. Recent discoveries of strong difference between transient bond lifetimes and the mechanical relaxation times in associating polymers challenged the classical theories. The bond lifetime renormalization model offers an interpretation of this effect. In order to provide detailed test of this model, we study telechelic associating polymers with different molecular weights and strong variations in strength of associations of the end groups. Using oscillatory shear rheology and dielectric spectroscopy, we were able to measure mechanical relaxations and characteristic relaxation times of bond dissociations. Detailed analysis demonstrates reasonable agreement of the experimental data with the predictions of the bond lifetime renormalization model on a semi-quantitative level. Surprisingly, our results suggest a kind of entangled dynamics even for telechelic associating polymers with molecular weight significantly smaller than the entanglement molecular weight.
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Presenters
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SIRUI GE
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, USA
- Materials Science and Engineering, University of Tennessee