Viscoelastic Properties of Entangled Polymer. IV. Binary Blends of Monodisperse Homopolymers

Soong, David S.; Shen, M.; Hong, S. D.

doi:10.1122/1.549517

Cited by 14 publications

(3 citation statements)

References 6 publications

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“…Comparison of E 9 2 with literature data on different monodisperse polymer melts and concentrated solutions indicated good agreement over a wide range of shear rates (8). For the monodisperse polystyrene melts surveyed (9)(10)(11)(12), the value of m that gives a good fit of experimental data ranges from 0.80 to 0.89, whereas m is approximately 0.87 for monodisperse styrene-butadiene Fig.…”

Section: Discussionsupporting

confidence: 60%

Shear‐rate‐dependent viscosity of non‐Newtonian suspensions and entangled polymer systems

Soong

Shen

1980

Polymer Engineering & Sci

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A simple equation is proposed to calculate the shear‐rate‐dependent viscosities of entangled polymers and particle suspensions. The rate‐dependence of the viscosities is attributed to changes in certain structural parameters associated with the fluids, such as entanglement density or degree of particle agglomeration. The state of these structural parameters for fluids subjected to a given shear flow is determined by two competing process, i.e., structural breakdown and reformation, which in steady How arc in a state of dynamic equilibrium. For the polymer systems structural degradation and reformation are tantamount to entanglement loss and creation, whereas for the suspensions they are correlated with the particle breakup and flocculation. The regeneration process is driven by thermal diffusion and is assumed to be independent of shear rate. The degradation process is caused primarily by the imposed shear and is assumed to be proportional to the shear rate to a power m (0

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Section: Discussionsupporting

confidence: 60%

Shear‐rate‐dependent viscosity of non‐Newtonian suspensions and entangled polymer systems

Soong

Shen

1980

Polymer Engineering & Sci

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“…It involves a modification of the relaxation times for each component, depending on the composition of the blend. 15 But the expression of the modified relaxation times is not explicitly related to the pure individual relaxation times and to the weight fractions. This model has been successful for binary blends of narrow distribution polymers and has been extended to polydisperse homopolymers.16…”

Section: Introductionmentioning

confidence: 99%

“…lengths of chains, we suggested an average constraint release function R(t) as R(t) = 4> ( )(15) 1=1 leading to an average constraint release time:rw = f+"ñ(t)3 dt (16) voThe tube-renewal time rt; of an IV;-chain imbedded in such a tube is given by…”

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confidence: 99%

Molecular weight distribution dependence of the viscoelastic properties of linear polymers: the coupling of reptation and tube-renewal effects

Montfort¹,

Marin²,

Monge³

1986

Macromolecules

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Considering that the terminal relaxation of every chain in a linear melt is dominated by reptational and constraint release motions, we propose an expression for the relaxation modulus G(t) of entangled polymers as a function of the molecular weight distribution (MWD). The expressions of zero-shear viscosity rj0 and steady-state compliance =/e°d erived from G(t) describe correctly the experimental behavior: 0 scales with average molecular weight as 0 Mw3•4"3•8 for a constant polydispersity P; Je°i ncreases strongly with P and varies widely with the shape of MWD. We also predict a decrease of viscosity with polydispersity; this is a possible explanation of some experimental variations of viscosity, which do not follow the classical power law with Mw. The behavior expected for strictly monodisperse samples shows that it is necessary to consider a relaxation times distribution in the terminal region.

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Analysis of the thickening reaction of a sheet molding compound resin through the use of dynamic mechanical testing

Gruskiewicz¹,

Collister²

1982

Polymer Composites

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The change in viscoelastic response of an unsaturated polyester during the course of thickening with magnesium oxide was evaluated, Rheological measurements were obtained to describe the effects of thickening as functions of time and magnesium oxide concentration. Previous researchers have made similar evaluations utilizing Brookfield viscosities. However, the test geometry asociated with a Brookfield T‐bar spindle is not well defined and data interpretation is consequently obscured. A Rheometrics Thermal Mechanical Spectrometer was used to obtain dynamic mechanical measurements ranging across three decades of frequency. Values of the elastic shear modulus, G′, the viscous shear modulus, G″, and the complex viscosity, η*, were calculated.

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Viscoelastic Properties of Entangled Polymer. IV. Binary Blends of Monodisperse Homopolymers

Cited by 14 publications

References 6 publications

Shear‐rate‐dependent viscosity of non‐Newtonian suspensions and entangled polymer systems

Shear‐rate‐dependent viscosity of non‐Newtonian suspensions and entangled polymer systems

Molecular weight distribution dependence of the viscoelastic properties of linear polymers: the coupling of reptation and tube-renewal effects

Analysis of the thickening reaction of a sheet molding compound resin through the use of dynamic mechanical testing

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