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Stress Growth in Transient Polymer Networks under Startup Shear Flow

  • Tsuyoshi KogaEmail author
  • Fumihiko Tanaka
  • Isamu Kaneda
Part of the Progress in Colloid and Polymer Science book series (PROGCOLLOID, volume 136)

Abstract

We study the stress growth in transient networks of telechelic associating polymers under the startup shear flow within the framework of our recent nonaffine transient network theory. We show that a transient strain hardening takes place due to the nonlinearity in the tension-elongation relation of the main chain. We calculate the critical shear rate \(\gamma\dot,\) c for the strain hardening as a function of the chain nonlinearity, and the overshoot time t max as a function of the shear rate \(\gamma\dot,\) . The theoretical results are compared with experimental data on aqueous solutions of a hydrophobically modified ethoxylated urethane (HEUR). The experimental results are consistent with the theoretical prediction. By detailed comparisons, we find that the effect of the polydispersity in the chain length significantly affects the transient stress because the nonlinear stretching effect of shorter polymer chains appears at smaller strains.

Keywords

Startup flow Stress overshoot Strain hardening Transient network Associating polymer 

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Copyright information

© Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  1. 1.Department of Polymer Chemistry, Graduate School of EngineeringKyoto UniversityKyotoJapan

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