The experimental data of Matsumiya et al. [Macromolecules 51, 9710–9729 (2018)] for start-up and the steady-state elongational flow of monodisperse unentangled polystyrene PS27k and poly(p-tert-butylstyrene) PtBS53k melts are analyzed based on the relaxation spectrum of the Rouse model and a single integral constitutive equation. As shown by Lodge and Wu [Rheol. Acta 10, 539–553 (1971)], the stress tensor of the Rouse model is equivalent to the rubberlike-liquid constitutive equation, and the relaxation modes of Rouse chains can be represented by an ensemble of virtual viscoelastic “strands” with relaxation times and creation rates. Instead of the affine deformation hypothesis, we assume that due to the flow, strands are oriented and stretched. The use of a history integral avoids preaveraging of orientation and stretch. Stretch is limited by a finite conformational stretch parameter. We find good agreement between model predictions and experimental data for start-up and the steady-state elongational flow of melts PS27k and PtBS53k and qualitative agreement with stress-relaxation after the stop of elongation. Extension-thickening and extension-thinning observed are caused by finite chain stretch in combination with strand orientation. The model predicts a scaling exponent for high Weissenberg number elongational flows of in agreement with experimental evidence. The same scaling exponent was observed and predicted earlier for high Weissenberg number shear flows [R. Colby et al., Rheol. Acta, 46, 569–575 (2007)], and we show that the steady-shear data of unentangled polystyrene melts are in nearly quantitative agreement with model prediction assuming only the orientation of strands in the shear flow with no stretch.
Skip Nav Destination
Modeling nonlinear rheology of unentangled polymer melts based on a single integral constitutive equation
Article navigation
January 2020
Research Article|
January 01 2020
Modeling nonlinear rheology of unentangled polymer melts based on a single integral constitutive equation
Esmaeil Narimissa
;
Esmaeil Narimissa
a)
1
Department of Chemical Engineering, Technion—Israel Institute of Technology (IIT)
, Technion City, Haifa 32 000, Israel
2
Department of Chemical Engineering, Guangdong Technion—Israel Institute of Technology (GTIIT)
, Shantou 515063, China
a)Author to whom correspondence should be addressed; electronic mail: esmaeiln@technion.ac.il
Search for other works by this author on:
Manfred H. Wagner
Manfred H. Wagner
3
Polymer Engineering/Polymer Physics, Berlin Institute of Technology (TU Berlin)
, Ernst-Reuter-Platz 1, 10587 Berlin, Germany
Search for other works by this author on:
a)Author to whom correspondence should be addressed; electronic mail: esmaeiln@technion.ac.il
J. Rheol. 64, 129–140 (2020)
Article history
Received:
September 18 2019
Accepted:
December 05 2019
Citation
Esmaeil Narimissa, Manfred H. Wagner; Modeling nonlinear rheology of unentangled polymer melts based on a single integral constitutive equation. J. Rheol. 1 January 2020; 64 (1): 129–140. https://doi.org/10.1122/1.5128295
Download citation file:
Sign in
Don't already have an account? Register
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Could not validate captcha. Please try again.
Sign in via your Institution
Sign in via your InstitutionPay-Per-View Access
$40.00
Citing articles via
Related Content
Nonlinear rheology and dynamics of supramolecular polymer networks formed by associative telechelic chains under shear and extensional flows
Journal of Rheology (May 2020)
Experimental study of phase separation in dynamically asymmetric unentangled polymer blend
J. Chem. Phys. (December 2022)
Effects of substrate-blocks interactions on the phase behaviors of cylinder-forming block copolymers
AIP Advances (March 2011)
Simulation studies on architecture dependence of unentangled polymer melts
J. Chem. Phys. (February 2015)
A single-chain model for the linear viscoelasticity of unentangled melts of associating polymers
Journal of Rheology (November 2022)