Flow Birefringence of Polymer Solutions in Time‐Dependent Field

Osaki, Kunihiro; Bessho, Nobuo; Kojimoto, Tetsuya; Kurata, Michio

doi:10.1122/1.549553

Cited by 46 publications

(13 citation statements)

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“…The above correlations (Eqs. 6 and 7) have successfully described the experimental data for LDPE for strain up to 30, polybutadiene solution for strain up to 3.3 and polystyrene solution for strain up to 8 .…”

Section: Theoretical Backgroundsmentioning

confidence: 80%

Anomalous first normal stress difference behavior of polymer nanocomposites and liquid crystalline polymer composites

et al. 2013

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The first normal stress difference (N1) behavior of polymer nanocomposites and liquid crystalline polymer (LCP) composites is a measure of elasticity and is affected by shear stress as a result of morphological alterations at the molecular and nanostructure levels. In this study, the steady shear rheological behaviors of polylactide (PLA) and nanographite platelet (NGP) bionanocomposites containing 1, 2, 3, and 5 wt% nanofiller were investigated. The shear rheological properties of glass fiber‐filled LCPs (filler aspect ratio > 100) were also examined. One of the objectives of this study was to obtain a correlation between N1, filler contents, and shear stress/rate of the measurements. The results suggest that N1 in PLA/NGP bionanocomposites is dependent on the level of filler loading as well as the shear rate beyond a critical value. For the LCP systems, N1 is positive for the unfilled and negative for the glass fiber‐filled LCPs, respectively. A novel rectangular hyperbola model was successfully developed and utilized to fit the N1 data of the neat PLA and PLA/NGP composites as well as the unfilled LCPs. The anomalous N1 behavior of PLA/NGP and LCP composites was also thoroughly discussed in this study. POLYM. ENG. SCI., 54:1300–1312, 2014. © 2013 Society of Plastics Engineers

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Section: Theoretical Backgroundsmentioning

confidence: 80%

Anomalous first normal stress difference behavior of polymer nanocomposites and liquid crystalline polymer composites

et al. 2013

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“…However, little attention has been given so far to the effective role of end effects in flow birefringence experiments. Indeed, few studies [23][24][25] have shown that even large aspect ratios of order 8-10 were not sufficient to approach planar flows. The first systematic study on end effects in flow-induced birefringence experiments was conducted by McHugh et al [26].…”

Section: End Effects In Flow-induced Birefringence Experimentsmentioning

confidence: 98%

Lubricated optical rheometer for the study of two-dimensional complex flows of polymer melts

Soulages

Schweizer

Venerus

et al. 2008

Journal of Non-Newtonian Fluid Mechanics

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“…where p and n are the polymer stress and the birefringence ͑or ''refractive index''͒ tensors, respectively, and C b is called the ''stress-optical coefficient.'' This relationship has been generally found to hold in both transient and steady shear flows; 17,18 it can be, however, violated under fast stretching flows, 19,20 such as extensional flows or shear flow at very high shear rates. For these cases, the birefringence is expected to grow less rapidly with increasing flow strength than does the stress, and it would finally saturate when polymer chains are being fully extended.…”

Section: Introductionmentioning

confidence: 98%

Investigations on several empirical rules for entangled polymers based on a self-consistent full-chain reptation theory

Hua

2000

The Journal of Chemical Physics

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Empirical rules, including the stress-optical rule, the Cox-Merz rule, the Gleissle's mirror relation, and the Laun's rule, that provide important alternatives in obtaining rheological data for concentrated polymer liquids are investigated via stochastic simulations of a recently proposed full-chain reptation theory ͓Hua and Schieber, J. Chem. Phys. 109, 10018 ͑1998͔͒ capable of treating rigorously all fundamental effects for concentrated polymer systems. Theoretical investigations of these rules are important, for they provide strict consistency checks on the predictions of existing molecular theories; at the same time, the limitations of these rules may also be explored. The current simulation implies that deviations from these empirical rules are likely to be observed when polymer chain stretching becomes significant. The effects of molecular weight and molecular weight distribution on the applicability of these rules are inferred; accordingly, we are able to explain the essential feature of the experimental finding when deviations from the Cox-Merz rule were observed. On the other hand, the theory is slightly modified to account for the proper stress-optical relation so that it can be used to simulate directly the birefringence fields of complex flows without being restricted by the validity of the stress-optical rule. Despite its remarkable success in explaining many experimental findings, the theory is found to be unable to predict satisfactorily the Cox-Merz rule and other similar empirical relationships in the power-law region. The discrepancies seem to imply that certain important effects might still be missing in existing reptation theories, and we discuss this issue within the reptation picture.

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Flow Birefringence of Polymer Solutions in Time‐Dependent Field

Cited by 46 publications

References 0 publications

Anomalous first normal stress difference behavior of polymer nanocomposites and liquid crystalline polymer composites

Anomalous first normal stress difference behavior of polymer nanocomposites and liquid crystalline polymer composites

Lubricated optical rheometer for the study of two-dimensional complex flows of polymer melts

Investigations on several empirical rules for entangled polymers based on a self-consistent full-chain reptation theory

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