Inferring the Nonlinear Mechanisms of a Reversible Network

Luca Martinetti, Olivia Carey-De La Torre, Kenneth S Schweizer, Randy H Ewoldt

Research output: Contribution to journalArticle

Abstract

A key open question for transient polymer networks is the molecular reason underlying their elastic stiffening and viscous thickening nonlinearities, with the two prevailing conventional hypotheses being flow-induced (i) increase of the number density of elastically active network strands (i.e., bridging chains) and (ii) nonlinear elastic force-extension chain behavior. The objective of this work is to reliably infer, and theoretically justify, the mechanism driving the nonlinear response of unentangled reversible networks formed by semidilute aqueous solutions of poly(vinyl alcohol) (PVA) and sodium tetraborate (Borax), across a range of 11 compositions and Deborah number varying from ≲10-2 to ≲70. Weakly nonlinear perturbations from equilibrium are quantitatively analyzed via a strain stiffening transient network theory endowed with a single nonlinear parameter and a microscopic statistical mechanical theory for the deformation-induced change of local interchain packing due to conformational anisotropy and its influence on an effective transient cross-link density. As a result, network structuring through stretch-induced enhancement of interchain associations is shown to dominate the leading-order viscous and elastic nonlinearities over the entire range of compositions and frequencies considered. Furthermore, our theoretical approach allows for a quantitative rationalization for the magnitudes of the intrinsic nonlinearities that is in excellent agreement with observations.

Original languageEnglish (US)
Pages (from-to)8772-8789
Number of pages18
JournalMacromolecules
Volume51
Issue number21
DOIs
StatePublished - Nov 13 2018

Fingerprint

Sodium borate
Active networks
Circuit theory
Chemical analysis
Polymers
Anisotropy
Alcohols
sodium borate
borax

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry

Cite this

Inferring the Nonlinear Mechanisms of a Reversible Network. / Martinetti, Luca; Carey-De La Torre, Olivia; Schweizer, Kenneth S; Ewoldt, Randy H.

In: Macromolecules, Vol. 51, No. 21, 13.11.2018, p. 8772-8789.

Research output: Contribution to journalArticle

Martinetti, Luca ; Carey-De La Torre, Olivia ; Schweizer, Kenneth S ; Ewoldt, Randy H. / Inferring the Nonlinear Mechanisms of a Reversible Network. In: Macromolecules. 2018 ; Vol. 51, No. 21. pp. 8772-8789.
@article{516ae4edffaa422db5e6daf6c86846bd,
title = "Inferring the Nonlinear Mechanisms of a Reversible Network",
abstract = "A key open question for transient polymer networks is the molecular reason underlying their elastic stiffening and viscous thickening nonlinearities, with the two prevailing conventional hypotheses being flow-induced (i) increase of the number density of elastically active network strands (i.e., bridging chains) and (ii) nonlinear elastic force-extension chain behavior. The objective of this work is to reliably infer, and theoretically justify, the mechanism driving the nonlinear response of unentangled reversible networks formed by semidilute aqueous solutions of poly(vinyl alcohol) (PVA) and sodium tetraborate (Borax), across a range of 11 compositions and Deborah number varying from ≲10-2 to ≲70. Weakly nonlinear perturbations from equilibrium are quantitatively analyzed via a strain stiffening transient network theory endowed with a single nonlinear parameter and a microscopic statistical mechanical theory for the deformation-induced change of local interchain packing due to conformational anisotropy and its influence on an effective transient cross-link density. As a result, network structuring through stretch-induced enhancement of interchain associations is shown to dominate the leading-order viscous and elastic nonlinearities over the entire range of compositions and frequencies considered. Furthermore, our theoretical approach allows for a quantitative rationalization for the magnitudes of the intrinsic nonlinearities that is in excellent agreement with observations.",
author = "Luca Martinetti and {Carey-De La Torre}, Olivia and Schweizer, {Kenneth S} and Ewoldt, {Randy H}",
year = "2018",
month = "11",
day = "13",
doi = "10.1021/acs.macromol.8b01295",
language = "English (US)",
volume = "51",
pages = "8772--8789",
journal = "Macromolecules",
issn = "0024-9297",
publisher = "American Chemical Society",
number = "21",

}

TY - JOUR

T1 - Inferring the Nonlinear Mechanisms of a Reversible Network

AU - Martinetti, Luca

AU - Carey-De La Torre, Olivia

AU - Schweizer, Kenneth S

AU - Ewoldt, Randy H

PY - 2018/11/13

Y1 - 2018/11/13

N2 - A key open question for transient polymer networks is the molecular reason underlying their elastic stiffening and viscous thickening nonlinearities, with the two prevailing conventional hypotheses being flow-induced (i) increase of the number density of elastically active network strands (i.e., bridging chains) and (ii) nonlinear elastic force-extension chain behavior. The objective of this work is to reliably infer, and theoretically justify, the mechanism driving the nonlinear response of unentangled reversible networks formed by semidilute aqueous solutions of poly(vinyl alcohol) (PVA) and sodium tetraborate (Borax), across a range of 11 compositions and Deborah number varying from ≲10-2 to ≲70. Weakly nonlinear perturbations from equilibrium are quantitatively analyzed via a strain stiffening transient network theory endowed with a single nonlinear parameter and a microscopic statistical mechanical theory for the deformation-induced change of local interchain packing due to conformational anisotropy and its influence on an effective transient cross-link density. As a result, network structuring through stretch-induced enhancement of interchain associations is shown to dominate the leading-order viscous and elastic nonlinearities over the entire range of compositions and frequencies considered. Furthermore, our theoretical approach allows for a quantitative rationalization for the magnitudes of the intrinsic nonlinearities that is in excellent agreement with observations.

AB - A key open question for transient polymer networks is the molecular reason underlying their elastic stiffening and viscous thickening nonlinearities, with the two prevailing conventional hypotheses being flow-induced (i) increase of the number density of elastically active network strands (i.e., bridging chains) and (ii) nonlinear elastic force-extension chain behavior. The objective of this work is to reliably infer, and theoretically justify, the mechanism driving the nonlinear response of unentangled reversible networks formed by semidilute aqueous solutions of poly(vinyl alcohol) (PVA) and sodium tetraborate (Borax), across a range of 11 compositions and Deborah number varying from ≲10-2 to ≲70. Weakly nonlinear perturbations from equilibrium are quantitatively analyzed via a strain stiffening transient network theory endowed with a single nonlinear parameter and a microscopic statistical mechanical theory for the deformation-induced change of local interchain packing due to conformational anisotropy and its influence on an effective transient cross-link density. As a result, network structuring through stretch-induced enhancement of interchain associations is shown to dominate the leading-order viscous and elastic nonlinearities over the entire range of compositions and frequencies considered. Furthermore, our theoretical approach allows for a quantitative rationalization for the magnitudes of the intrinsic nonlinearities that is in excellent agreement with observations.

UR - http://www.scopus.com/inward/record.url?scp=85056202663&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85056202663&partnerID=8YFLogxK

U2 - 10.1021/acs.macromol.8b01295

DO - 10.1021/acs.macromol.8b01295

M3 - Article

VL - 51

SP - 8772

EP - 8789

JO - Macromolecules

JF - Macromolecules

SN - 0024-9297

IS - 21

ER -