Rheology of Poly(ethylene oxide)/Organoclay Nanocomposites

Hyun, Yang H.; Lim, Sang Kyoo; Choi, Hyoung Jin; Jhon, Myung S.

doi:10.1021/ma002191w

Cited by 356 publications

(202 citation statements)

References 54 publications

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“…Furthermore, because the clay platelets align during flow, the power-law index for PNC is smaller after shearing than before (24). When the clay content increases, the transition from the Newtonian to the power-law flow region shifts toward lower frequency (17,20,28). Especially, at high clay loadings (e.g., w Ն 10 wt%), the Newtonian plateau disappears for frequencies w Ն 0.1 rad/s.…”

Section: Introduction Generalmentioning

confidence: 99%

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Melt compounding of different grades of polystyrene with organoclay. Part 2: Rheological properties

Tanoue

Utracki

García‐Rejón

et al. 2004

Polymer Engineering & Sci

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Polystyrene‐based nanocomposites (PNC) were prepared using three grades of polystyrene (different molecular weights). The resin was melt‐compounded with 0 to 10 wt% of commercial organoclay in a co‐rotating twin‐screw extruder. Owing to thermo‐oxidative degradation the degree of dispersion was poor. The rheological properties of PNC were determined under dynamic and steady state shear as well as under extensional flow conditions. At the higher clay content, dynamic strain sweep demonstrated that the storage and loss moduli decrease continuously with an increase of strain. To characterize this nonlinear viscoelastic behavior, the Fourier‐transform rheology was applied. The low strain frequency sweep showed that the storage and loss moduli increase with organoclay content. The extracted zero‐shear viscosity data were used to calculate the intrinsic viscosity and then the aspect ratio of dispersions. In spite of nonlinear viscoelastic behavior, the time‐temperature superposition was observed in the full range of concentration. The horizontal and vertical shift factors were found to be almost independent of organoclay content and molecular weight of PS. For comparison, PNC was also prepared by the solution method. A high degree of dispersion was obtained, reflected in the aspect ratio: p = 269, to be compared with p = 16 calculated for the melt‐compounded PNC. Polym. Eng. Sci. 44:1061–1076, 2004. © 2004 Society of Plastics Engineers.

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Section: Introduction Generalmentioning

confidence: 99%

“…PCL (16), polypropylene (PP) (17,18), PA-12 (19), PEG (20), poly(styrene-b-isoprene) PS-PI block copolymer (21,22), PS (23Ϫ25), etc. The values of the initial slope, gЈ or g Љ, depend on the degree of dispersion and concentration of organoclay platelets.…”

Section: Introduction Generalmentioning

confidence: 99%

Melt compounding of different grades of polystyrene with organoclay. Part 2: Rheological properties

Tanoue

Utracki

García‐Rejón

et al. 2004

Polymer Engineering & Sci

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“…The Carreau fluid model can well characterize the rheology of various polymeric solutions, such as 1% methylcellulose tylose in glycerol solution and 0.3% hydroxyethyl-cellulose Natrosol HHX in glycerol solution 3 and pure poly ethylene oxide. 4 These polymers are widely used in capillary electrophoresis to improve the resolution in the separation of proteins 5 and DNAs. 6 It determines a specific region where the fluid viscosity and its shear rate has a linear relationship (on the usual log-log coordinates).…”

Section: Introductionmentioning

confidence: 99%

Boundary layer flow and heat transfer to Carreau fluid over a nonlinear stretching sheet

2015

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This article studies the Carreau viscosity model (which is a generalized Newtonian model) and then use it to obtain a formulation for the boundary layer equations of the Carreau fluid. The boundary layer flow and heat transfer to a Carreau model over a nonlinear stretching surface is discussed. The Carreau model, adequate for many non-Newtonian fluids, is used to characterize the behavior of the fluids having shear thinning properties and fluids with shear thickening properties for numerical values of the power law exponent n. The modeled boundary layer conservation equations are converted to non-linear coupled ordinary differential equations by a suitable transformation. Numerical solution of the resulting equations are obtained by using the Runge-Kutta Fehlberg method along with shooting technique. This analysis reveals many important physical aspects of flow and heat transfer. Computations are performed for different values of the stretching parameter (m), the Weissenberg number (We) and the Prandtl number (Pr). The obtained results show that for shear thinning fluid the fluid velocity is depressed by the Weissenberg number while opposite behavior for the shear thickening fluid is observed. A comparison with previously published data in limiting cases is performed and they are in excellent agreement.

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“…Depending on the material characteristics, the resultant response represents solid-like or liquid-like behaviour. By definition, materials behave like a solid for G′ > G″, and like a fluid for G′ < G″ [15,16]. Fig.…”

Section: Resultsmentioning

confidence: 99%

Relationship between structural evolution and rheological measurements for polymer + organoclay nanocomposites

et al. 2005

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Nanocomposites with synthetic biodegradable aliphatic polyesters (BAP) were synthesized by the solution intercalation method with addition of organically modified montmorillonite. The hybrid structural evolution, caused by nanoscopic interaction between matrix polymer and layered silicate, was analyzed using viscoelastic properties obtained from oscillatory rheological measurements. Changes of viscoelastic properties to more solid-like, especially in the terminal region, were explained by both formation of specific BAP chain mesostructures with organoclay incorporated and a rheological percolation threshold. This behaviour was analyzed via a modified Cole-Cole plot evaluating the structural changes with filler concentration as well as the frequency dependence of dynamic modulus, complex modulus, and phase angle. Furthermore, the stress relaxation behaviour successfully demonstrated structural changes and critical concentration of nanocomposites with a jump shift of the longest relaxation time towards longer time.

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Rheology of Poly(ethylene oxide)/Organoclay Nanocomposites

Cited by 356 publications

References 54 publications

Melt compounding of different grades of polystyrene with organoclay. Part 2: Rheological properties

Melt compounding of different grades of polystyrene with organoclay. Part 2: Rheological properties

Boundary layer flow and heat transfer to Carreau fluid over a nonlinear stretching sheet

Relationship between structural evolution and rheological measurements for polymer + organoclay nanocomposites

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