Necessary conditions for shear thickening in associating polymer networks

2007 ◽  
Vol 141 (1) ◽  
pp. 18-42 ◽  
Author(s):  
Tsutomu Indei
Keyword(s):  
Necessary Conditions ◽  
Polymer Networks ◽  
Shear Thickening ◽  
Associating Polymer

Bond kinetics in simulated telechelic associating polymer networks

2016 ◽  
Vol 13 (10/11/12) ◽  
pp. 935
Author(s):  
Mark Wilson ◽  
Avinoam Rabinovitch ◽  
Arlette R.C. Baljon
Keyword(s):  
Polymer Networks ◽  
Bond Kinetics ◽  
Associating Polymer

Effects of fluctuations of cross-linking points on viscoelastic properties of associating polymer networks

2012 ◽  
Vol 51 (11-12) ◽  
pp. 1021-1039 ◽  
Author(s):  
Tsutomu Indei ◽  
Jay D. Schieber ◽  
Jun-ichi Takimoto
Keyword(s):  
Viscoelastic Properties ◽  
Polymer Networks ◽  
Cross Linking ◽  
Associating Polymer

scholarly journals The Chain Distribution Tensor: Linking Nonlinear Rheology and Chain Anisotropy in Transient Polymers

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 848 ◽  
Author(s):  
Shankar Lalitha Sridhar ◽  
Franck Vernerey
Keyword(s):  
Shear Rate ◽  
Polymer Networks ◽  
Shear Thickening ◽  
Shear Thinning ◽  
Underlying Mechanism ◽  
Weissenberg Number ◽  
Critical Shear Rate ◽  
Nonlinear Rheology ◽  
Non Gaussian ◽  
Chain Force

Transient polymer networks are ubiquitous in natural and engineered materials and contain cross-links that can reversibly break and re-form. The dynamic nature of these bonds allows for interesting mechanical behavior, some of which include nonlinear rheological phenomena such as shear thickening and shear thinning. Specifically, physically cross-linked networks with reversible bonds are typically observed to have viscosities that depend nonlinearly on shear rate and can be characterized by three flow regimes. In slow shear, they behave like Newtonian fluids with a constant viscosity. With further increase in shear rate, the viscosity increases nonlinearly to subsequently reach a maximum value at the critical shear rate. At this point, network fracture occurs followed by a reduction in viscosity (shear-thinning) with a further increase in shear rate. The underlying mechanism of shear thickening in this process is still unclear with debates between a conversion of intra-chain to inter-chain cross-linking and nonlinear chain stretch under high tension. In this paper, we provide a new framework to describe the nonlinear rheology of transient polymer networks with the so-called chain distribution tensor using recent advances from the transient network theory. This tensor contains quantitatively and statistical information of the chain alignment and possible anisotropy that affect network behavior and mechanics. We investigate shear thickening as a primary result of non-Gaussian chain behavior and derive a relationship for the nonlinear viscosity in terms of the non-dimensional Weissenberg number. We further address the criterion for network fracture at the critical shear rate by introducing a critical chain force when bond dissociation is suddenly accelerated. Finally, we discuss the role of cross-linker density on viscosity using a “sticky” reptation mechanism in the context of previous studies on metallo-supramolecular networks with reversible cross-linkers.

scholarly journals Associating Polymer Networks Based on Cyclodextrin Inclusion Compounds for Heavy Oil Recovery

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Xi Li ◽  
Zheng Shu ◽  
Pingya Luo ◽  
Zhongbin Ye
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
Polymer Networks ◽  
Adsorbed Layer ◽  
Water Soluble ◽  
Heavy Oil Recovery ◽  
Original Oil In Place ◽  
Hydrolyzed Polyacrylamide ◽  
The Relationship ◽  
Associating Polymer

This work evaluates an approach to improve the enhanced heavy oil recovery performance of hydrophobic associating polymer. A polymeric system based on water-soluble hydrophobic associating polymer (WSHAP) and cyclodextrin (CD) polymer was proposed in this work. Addition of CD polymer to WSHAP forms interpolymer bridges by inclusion of CD groups with hydrophobic tails, and thereby the network structure is strengthened. The proposed system offers good viscoelasticity, pronounced shear thinning, and interesting viscosity-temperature relations. Sand pack tests indicated that the proposed system can build high resistance factor during the propagation in porous media, and its moderate adsorption phenomenon was represented by the thickness of the adsorbed layer. The relationship between effective viscosity and oil recovery increment indicated that the proposed system can significantly reduce the residual oil saturation due to the “piston-like” propagation. The overall oil recovery was raised by 5.7 and 24.5% of the original oil in place compared with WSHAP and partially hydrolyzed polyacrylamide (HPAM), respectively.

scholarly journals Mechanism of Shear Thickening in Reversibly Cross-Linked Supramolecular Polymer Networks

2010 ◽  
Vol 43 (7) ◽  
pp. 3556-3565 ◽  
Author(s):  
Donghua Xu ◽  
Jennifer L. Hawk ◽  
David M. Loveless ◽  
Sung Lan Jeon ◽  
Stephen L. Craig
Keyword(s):  
Polymer Networks ◽  
Shear Thickening ◽  
Supramolecular Polymer
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