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Rheology and Dynamics of Associative Polymers in Shear and Extension: Theory and Experiment

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Show simple item record Tripathi, Anubhav Tam, Kam C. McKinley, Gareth H. 2005-08-22T19:34:56Z 2005-08-22T19:34:56Z 2005-08-22T19:34:56Z
dc.description Submitted to Macromolecules, July 2005 en
dc.description.abstract We investigate the steady and transient shear and extensional rheological properties of a series of model hydrophobically modified ethoxylate-urethane (HEUR) polymers with varying degrees of hydrophobicity. A new nonlinear two-species network model for these telechelic polymers is described which incorporates appropriate molecular mechanisms for the creation and destruction of elastically-active chains. Like other recent models we incorporate the contributions of both the bridging chains (those between micelles) and the dangling chains to the final stress tensor. This gives rise to two distinct relaxation time scales; a short Rouse time for the relaxing chains and a longer network time–scale that depends on the aggregation number and strength of the micellar junctions. The evolution equations for the fraction of elastically-active chains and for the conformation tensors of each species are solved to obtain the total stress arising from imposed deformations. The model contains a single non-linear parameter and incorporates the non-linear chain extension, the shear-induced enhancement of associations and the stretch-induced dissociation of hydrophobic chains. In contrast to earlier closed-form models, we are able to obtain quantitative agreement between experimental measurements and the model predictions for three different series of telechelic polymers over a range of concentrations. The scaling of both the zero shear viscosity and the effective network relaxation time show good agreement with those measured in experiments. The model also quantitatively captures both the shear-thickening and subsequent shear-thinning observed in the rheology at high deformation rates and predicts transient extensional stress growth curves in close agreement with those measured using a filament stretching rheometer. en
dc.description.sponsorship Schlumberger Foundation en
dc.format.extent 942401 bytes
dc.format.mimetype application/pdf
dc.language.iso en_US en
dc.relation.ispartofseries 05-P-10 en
dc.subject Associative polymers en
dc.subject Telechelic polymers en
dc.subject HEUR en
dc.subject Constitutive model en
dc.subject Extensional rheology en
dc.subject Shear rheology en
dc.title Rheology and Dynamics of Associative Polymers in Shear and Extension: Theory and Experiment en
dc.type Preprint en

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