Constitutive model that predicts stress overshoot and shear thinning for entangled melts
(2017) 88th Annual Meeting-SoR_Abst_172 — Location: Tampa , Florida, USA (12.February.2017)
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- Authors
Taghipour, Hamid 
- Abstract
- We review constitutive modeling of melts of linear polymers, focusing on changes in bulk rheological response in startup shear flow. The time dependent rheological anomalies are captured by constitutive equations, originate from the MLD model and Rolie–Poly equation for entangled melts. According to these models and supporting experimental data, for melts, the shear viscosity decrease dramatically by increasing the shear rate as the entanglement density increases. However the shear stress growth and first normal stress coefficients do not increase monotonically but pass through a maximum with increasing time or strain at sufficiently high shear rates. The stress overshoot which occurs at rates between the reciprocal of the Rouse time and of the reptation time have been attributed to CCR and alignment of the primitive chain. In particular this initial stress overshoot is basically due to chain retraction after affine deformation rather than chain orientation.
- Affiliations
UBC Department of Chemical and Biological Engineering
Citations
Taghipour, H., Ebrahimi, T., Mehrkhodavandi, P., G. Hatzikiriakos, S., & Van Ruymbeke, E. (2017). Constitutive model that predicts stress overshoot and shear thinning for entangled melts. In Albert, Co (ed.), 88 TH ANNUAL MEETING PROGRAM AND ABSTRACTS. https://hdl.handle.net/2078.5/220169