Nonlinear Stress Relaxation of End-associative Hydrophobically Modified Ethoxylated Urethane (HEUR) Solutions under Step Strain

Yu-Xuan Pei; Quan Chen; Hiroshi Watanabe

doi:10.1007/s10118-026-3573-1

Your Location：

Home >

Browse articles >

Nonlinear Stress Relaxation of End-associative Hydrophobically Modified Ethoxylated Urethane (HEUR) Solutions under Step Strain

Special Topic: Functional Gels | Updated：2026-05-30

- Nonlinear Stress Relaxation of End-associative Hydrophobically Modified Ethoxylated Urethane (HEUR) Solutions under Step Strain
- Nonlinear Stress Relaxation of End-associative Hydrophobically Modified Ethoxylated Urethane (HEUR) Solutions under Step Strain
- Chinese Journal of Polymer Science 2026年44卷第6期页码：1790-1803
- Affiliations：
  
  a.State Key Laboratory of Polymer Science and Technology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
  b.School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China
  c.Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
- Author bio：
  
  qchen@ciac.ac.cn (Q.C.)
  hiroshi@scl.kyoto-u.ac.jp (H.W.)
- Funds：
  
  This work was financially supported by the National Natural Science Foundation of China (Nos. 52425301 and 22173095).;Quan Chen is an editorial board member for Chinese Journal of Polymer Science and was not involved in the editorial review orthe decision to publish this article. All authors declare that thereare no competing interests.The data that support the findings of this study are available from the corresponding author upon reasonable request.
- DOI：10.1007/s10118-026-3573-1
  中图分类号：
- 收稿：2025-12-12，
  
  修回：2026-01-09，
  
  录用：2026-01-13，
  
  网络首发：2026-03-20，
  
  纸质出版：2026-06-05
- Accepted：
Scan QR Code
Pei, Y. X.; Chen, Q.; Watanabe, H. Nonlinear stress relaxation of end-associative hydrophobically modified ethoxylated urethane (HEUR) solutions under step strain. Chinese J. Polym. Sci. 2026, 44, 1790–1803

Yu-Xuan Pei, Quan Chen, Hiroshi Watanabe. Nonlinear Stress Relaxation of End-associative Hydrophobically Modified Ethoxylated Urethane (HEUR) Solutions under Step Strain[J]. Chinese Journal of Polymer Science, 2026, 44(6): 1790-1803.
Pei, Y. X.; Chen, Q.; Watanabe, H. Nonlinear stress relaxation of end-associative hydrophobically modified ethoxylated urethane (HEUR) solutions under step strain. Chinese J. Polym. Sci. 2026, 44, 1790–1803 DOI： 10.1007/s10118-026-3573-1.

Yu-Xuan Pei, Quan Chen, Hiroshi Watanabe. Nonlinear Stress Relaxation of End-associative Hydrophobically Modified Ethoxylated Urethane (HEUR) Solutions under Step Strain[J]. Chinese Journal of Polymer Science, 2026, 44(6): 1790-1803. DOI： 10.1007/s10118-026-3573-1.

摘要

Nonlinear softening factor

eff

of hydrophobically modified ethoxylated urethane (HEUR)-aq. solutions at long times

defined with respect to short-time hardened state

is considerably well described by a simple model formulating strain-induced HEUR micelle fusion followed by micelle opening/splitting associated with a free energy increase

$$ \langle \Delta F/k_{\mathrm{B}} T \rangle $$

https://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=109377020&type=

https://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=109377020&type=small

http://notExist.jpg

under strain.

Abstract

Nonlinear stress relaxation under step strain

was examined for aqueous solutions of an end-associative telechelic polymer

hydrophobically modified ethoxylated urethane (HEUR) having hexadecyl groups at the two ends of the chain. At 20 °C where the end hexadecyl groups were in the molten liquid state

the solutions with the HEUR concentrations

=1 wt% and 5 wt% commonly exhibited strain-hardening at short time

and the strain-softening (damping) at long

. In the terminal relaxation zone at sufficiently long

the nonlinear relaxation modulus

(

) was found to obey the time-strain separability. These nonlinear features were discussed in relation to strain-

induced changes in the associative network structure. In the aqueous HEUR solutions

aggregates of the precipitated end-groups should be stabilized by loops of dissolved HEUR backbones to form so-called flower micelles. At low

most of those micelles would connect HEUR chains into a long linear sequence referred to as superbridge

thereby forming a sparse network. At higher

those superbridges would become shorter to densify the network accordingly. Immediately after imposition of the large step strain

the flower micelles in the superbridge backbone would fuse each other to form a denser network thereby exhibiting the hardening. This micelle fusion would be more significant for longer superbridges to enhance the strain hardening at lower

. After this fusion

the micelles having liquid cores would be opened up because of the enhanced tension of the deformed superbridge

and then split to disconnect the superbridge if this tension overwhelms the micelle strength. This opening/splitting process possibly resulted in the partial breakage of the network and the corresponding softening. Finally

the surviving part of the network would relax on thermal dissociation of the remaining micelles thereby exhibiting the time-strain separable damping at long

. These features were semi-quantitatively described by a simple model that considered the strain-induced fusion followed by mechanical opening/breakage of the transient crosslinks.

关键词

Keywords

references

Annable, T.; Buscall, R.; Ettelaie, R.; Whittlestone, D. The rheology of solutions of associating polymers: Comparison of experimental behavior with transient network theory. J. Rheol. 1993 , 37 , 695−726..

Annable, T.; Buscall, R.; Ettelaie, R. Network formation and its consequences for the physical behaviour of associating polymers in solution. Colloids Surf. A 1996 , 112 , 97−116..

Xu, B.; Li, L.; Yekta, A.; Masoumi, Z.; Kanagalingam, S.; Winnik, M. A.; Zhang, K. W.; Macdonald, P. M. Synthesis, characterization, and rheological behavior of polyethylene glycols end-capped with fluorocarbon hydrophobes. Langmuir 1997 , 13 , 2447−2456..

Tam, K. C.; Jenkins, R. D.; Winnik, M. A.; Bassett, D. R. A structural model of hydrophobically modified urethane-ethoxylate (HEUR) associative polymers in shear flows. Macromolecules 1998 , 31 , 4149−4159..

Tripathi, A.; Tam, K. C.; McKinley, G. H. Rheology and dynamics of associative polymers in shear and extension: Theory and experiments. Macromolecules 2006 , 39 , 1981−1999..

Berret, J. F.; Séréo, Y.; Winkelman, B.; Calvet, D.; Collet, A.; Viguier, M. Nonlinear rheology of telechelic polymer networks. J. Rheol. 2001 , 45 , 477−492..

Berret, J. F.; Séréro, Y. Evidence of shear-induced fluid fracture in telechelic polymer networks. Phys. Rev. Lett. 2001 , 87 , 048303..

Ma, S. O. X.; Cooper, S. L. Shear thickening in aqueous solutions of hydrocarbon end-capped poly(ethylene oxide). Macromolecules 2001 , 34 , 3294−3301..

Pellens, L.; Corrales, R. G.; Mewis, J. General nonlinear rheological behavior of associative polymers. J. Rheol. 2004 , 48 , 379−393..

Pellens, L.; Ahn, K. H.; Lee, S. J.; Mewis, J. Evaluation of a transient network model for telechelic associative polymers. J. Non-Newtonian Fluid Mech. 2004 , 121 , 87−100..

Pellens, L.; Vermant, J.; Mewis, J. Deviations from the stress-optical rule in telechelic associative polymer solutions. Macromolecules 2005 , 38 , 1911−1918..

Suzuki, S.; Uneyama, T.; Inoue, T.; Watanabe, H. Nonlinear rheology of telechelic associative polymer networks: Shear thickening and thinning behavior of hydrophobically modified ethoxylated urethane (HEUR) in aqueous solution. Macromolecules 2012 , 45 , 888−898..

Uneyama, T.; Suzuki, S.; Watanabe, H. Concentration dependence of rheological properties of telechelic associative polymer solutions. Phys. Rev. E 2012 , 86 , 031802..

Suzuki, S.; Uneyama, T.; Watanabe, H. Concentration dependence of nonlinear rheological properties of hydrophobically modified ethoxylated urethane aqueous solutions. Macromolecules 2013 , 46 , 3497−3504..

Marrucci, G.; Bhargava, S.; Cooper, S. L. Models of shear-thickening behavior in physically crosslinked networks. Macromolecules 1993 , 26 , 6483−6488..

Tanaka, F.; Edwards, S. F. Viscoelastic properties of physically crosslinked networks. 1. Transient network theory. Macromolecules 1992 , 25 , 1516−1523..

Tanaka, F.; Koga, T. Nonaffine transient network theory of associating polymer solutions. Macromolecules 2006 , 39 , 5913−5920..

Koga, T.; Tanaka, F.; Kaneda, I.; Winnik, F. M. Stress buildup under start-up shear flows in self-assembled transient networks of telechelic associating polymers. Langmuir 2009 , 25 , 8626−8638..

Koga, T.; Tanaka, F. Theor etical predictions on normal stresses under shear flow in transient networks of telechelic associating polymers. Macromolecules 2010 , 43 , 3052−3060..

Indei, T.; Koga, T.; Tanaka, F. Theory of shear-thickening in transient networks of associating polymer. Macromol. Rapid Commun. 2005 , 26 , 701−706..

Ahmadi, M.; Hawke, L. G. D.; Goldansaz, H.; van Ruymbeke, E. Dynamics of entangled linear supramolecular chains with sticky side groups: influence of hindered fluctuations. Macromolecules 2015 , 48 , 7300−7310..

Hu, X. B.; Vatankhah-Varnoosfaderani, M.; Zhou, J.; Li, Q. X.; Sheiko, S. S. Weak hydrogen bonding enables hard, strong, tough, and elastic hydrogels. Adv. Mater. 2015 , 27 , 6899−6950..

Scherz, L. F.; Costanzo, S.; Huang, Q.; Schlütter, A. D.; Vlassopoulos, D. Dendronized polymers with ureidopyrimidinone groups: An efficient strategy to tailor intermolecular interactions, rheology, and fracture. Macromolecules 2017 , 50 , 5176−5187..

Zhang, Z. J.; Liu, C.; Cao, X.; Gao, L. C.; Chen, Q. Linear viscoelastic and dielectric properties of strongly hydrogen-bonded polymers near the sol-gel transition. Macromolecules 2016 , 49 , 9192−9202..

Parisi, D.; Ditillo, C. D.; Han, A. J.; Lindberg, S.;Hamersky, M. W.; Colby, R. H. Rheological investigation on the associative properties of poly(vinyl alcohol) solutions. J. Rheol. 2022 , 66 , 1141−1150..

Chassenieux, C.; Tassin, J. F.; Gohy, J. F.; Jérôme, R. Elongation of telechelic ionomers under shear: a rheological and rheo-optical study. Macromolecules 2000 , 33 , 1796−1800..

Qiao, X.; Weiss, R. A. Nonlinear rheology of lightly sulfonated polystyrene ionomers. Macromolecules 2013 , 46 , 2417−2424..

Chen, Q.; Huang, C.; Weiss, R. A.; Colby, R. H. Viscoelasticity of reversible gelation for ionomers. Macromolecules 2015 , 48 , 1221−1230..

Huang, C.; Chen, Q.; Weiss, R. A. Rheological behavior of partially neutralized oligomeric sulfonated polystyrene ionomers. Macromolecules 2017 , 50 , 424−431..

Zhang, Z. J.; Chen, Q.; Colby, R. H. Dynamicsof associative polymers. Soft Matter. 2018 , 14 , 2961−2977..

Pei, Y. X.; Chen, Q.; Matsumiya, Y.; Watanabe, H. Nonlinear relaxation of unentangled associative polymers: strain-induced hardening and softening. Macromolecules 2025 , 58 , 953−967..

Kawaguchi, S.; Imai, G.; Suzuki, J.; Miyahara, A.; Kitano, T.; Ito, K. Aqueous solution properties of oligo- and poly(ethylene oxide) by static light scattering and intrinsic viscosity. Polymer 1997 , 38 , 2885−2891..

Wagner, H. L. The Mark-Houwink-Sakurada equation for the viscosity of atactic polystyrene. J. Phys. Chem. Ref. Data 1985 , 14 , 1101−1106..

Watanabe, H. Viscoelasticity and dynamics of entangled polymers. Prog. Polym. Sci. 1999 , 24 , 1253−1403..

浏览量

Downloads

CSCD

文章被引用时，请邮件提醒。

Submit

工具集

关联资源

Strain Softening of Styrene-Isoprene-Styrene Copolymers under Large Amplitude Oscillatory Shear for Clarifying Payne Effect in Rubbers and Their Nanocomposites

Circularly Polarized Luminescence Based on Helical Polymers: Structure-Property Relationships and Regulation Mechanisms

2026-9 Contents

Sliding Dynamics of Ring Chain on a Rod-Coil Block Copolymer in Rotaxane

Alternating Poly(ether-alt-ester)s with High Glass Transition Temperature Enabled by Rotationally Constrained Biaryl Units