Viscoelastic Properties of Concentrated Solutions of Poly(methyl methacrylate) in Diethyl Phthalate

Masuda, Toshiro; Toda, Namihiro; Aoto, Yoshio; Onogi, Shigeharu

doi:10.1295/polymj.3.315

Cited by 48 publications

(54 citation statements)

References 12 publications

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“…It is difficult to determine the entanglement modulus accurately from the height of the plateau. According to Sanders et a!., 19 • 24 or the entanglement compliance can be evaluated by integration of G" over the region of In w encompassing the maximum of G ", (8) In practice, a G" vs. In w curve is numerically integrated from In w=-oo to the maximum of G ", and the result is doubled.…”

Section: Viscoelastic Properties In the Rubbery Regionmentioning

confidence: 99%

Concentration Dependence of Viscoelastic Properties of a Mixture of Three- and Four-Branched Star Polystyrenes

Masuda

Ohta

Kitamura

et al. 1981

Polym J

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ABSTRACT:Viscoelastic properties of concentrated solutions of a mixture of three-and fourbranched polystyrenes were measured by means of a concentric cylinder type rheometer. The Vogel parameters, IXr and T0 , were calculated from the temperature dependence of viscosity and the shift factor aT. From the frequency dependence of the storage shear modulus G' and the loss modulus G ",the characteristic parameters in the terminal zone such as zero-shear viscosity 1' /o and steadystate compliance J, 0 were evaluated. The dependence of these parameters on concentration was compared with that of concentrated solutions of linear polystyrenes. The concentration dependence of170 for star polymers is very similar to that for linear ones. However, J, 0 for the mixture of threeand four-branched polystyrenes showed unusual behavior that was quite different from that oflinear polymer and monodisperse star polymer. The entanglement compliance is also discussed.KEY WORDS Viscoelasticity I Polystyrene I Branched Polymer I Viscosity I Steady-State Compliance I Vogel Parameters I Concentration Dependence I In our previous papers, the rheological properties in the rubbery and flow regions of concentrated solutions and melts of star-shaped polystyrene mixtures1·2 and randomly branched polystyrenes 3 were investigated. In these experiments, we noted the unusual behavior that the steady-state compliance J. 0 of concentrated solutions of mixtures of threeand four-branched polystyrenes is much lower than those of the undiluted ones. 1 Moreover, 1. 0 for 90 wt% solutions was independent of molecular weight, but that of 50 wt% solutions proportionally increased with molecular weight in the entanglement region. 2 This behavior of 1. 0 observed for mixtures 2 is quite different from that for linear polymers 4 -9 and also from star-shaped polymers with no distribution in the number and length of branches. 10 -17 ture T0 , temperature coefficient of free volume IXr, zero-shear viscosity 1] 0 , and steady-state compliance J. 0 . The experimental results were compared with those for concentrated solutions of linear polystyrenes.9·17In the present paper, the dynamic viscoelastic properties for concentrated solutions of mixtures of three-and four-branched star polystyrenes have been measured to determine the concentration dependence ofparameters 5 such as the Vogel tempera-* Rheologicai Properties of Anionic Polystyrenes. X. EXPERIMENTAL MaterialsOne (LB17) of the star-shaped polystyrene samples used in a previous study, 1 which was a mixture of three-and four-branched polymers, was taken for this study.preparative procedure of this star polystyrene is the same as that described before 1 · 2 and was not repeated. The gel permeation chromatograms and the sedimentation patterns of this sample were also similar to those reported in the previous paper. 2 For comparison, a narrow-distribution linear polystyrene sample L50 was also examined. 17 The weight-and number-average molecular weights, M wl Mn, and the coupling ratio P (the ratio of Mn of the star...

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Section: Viscoelastic Properties In the Rubbery Regionmentioning

confidence: 99%

Concentration Dependence of Viscoelastic Properties of a Mixture of Three- and Four-Branched Star Polystyrenes

Masuda

Ohta

Kitamura

et al. 1981

Polym J

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“…The above stated difference in the behavior of ACM and NBR systems might be explained in terms of the difference in the shape of the chain, polymer-polymer (2,2), and solvent-polymer (1,2) interactions. In the case of ACM systems the 2,2 interaction is stronger than and relatively favored over the 1,2 interaction.…”

Section: Resultsmentioning

confidence: 99%

“…Many investigators have reached a similar conclusion with a number of model polymers that are nonpolar and have very narrow molecular weight distributions. [1][2][3][4][5][6][7][8][9] However, this result is different from the observation of Nakajima and Okuno 11 in their work on NBR-plasticizer systems.…”

Section: Polar Solvent Effect On Dynamic Modulimentioning

confidence: 85%

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Effect of polar solvents on dynamic moduli of concentrated solutions of polyethylacrylate

Nakajima¹,

Varkey²

1998

J. Appl. Polym. Sci.

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There have been many investigations on the effect of solvents on the dynamic moduli of concentrated polymer solutions. However, most of the polymers investigated were nonpolar, such as polystyrenes and polybutadienes. Moreover, the samples were usually model polymers of very narrow molecular weight distribution and were either linear or branched star. Our investigation was on a commercial polymer, which is polar and has long branches but is ''gel free.'' The solvents used were polar plasticizers. This study was motivated by the frequent observation that a small addition of plasticizers has little effect on the rubbery modulus or has an unexpectedly large reduction of the rubbery modulus, depending on a polymer-plasticizer pair. This work examines concentrated solutions of polyethylacrylate and three plasticizers (DBP, DHP, and DOP) at concentrations above 50% for DBP and DHP and above 80% for DOP. DOP did not dissolve the rubber at the lower concentrations. The temperature range was 30 -150°C, and the frequency range was 10 Ϫ2-10 2 rad/s. The time-temperature correspondence was applicable over the entire range of observation. The rubbery modulus was found to be independent of the plasticizer type at all concentrations. With dilution to 90% of polymer there was only small decrease of the modulus, and with further dilution the modulus decreased with a slope of 1.8 in the double-logarithmic plot of the modulus against concentration.

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“…Then, the second invariant of the rate of strain tensor is given by ( 6) Therefore, the average rate of strain between t=O and t= t is given by…”

Section: Methodsmentioning

confidence: 99%

Extensional and Fractural Properties of Concentrated Solutions of Monodisperse Polystyrene at Elevated Temperatures

Kamei

Onogi

1976

Polym J

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Viscoelastic Properties of Concentrated Solutions of Poly(methyl methacrylate) in Diethyl Phthalate

Cited by 48 publications

References 12 publications

Concentration Dependence of Viscoelastic Properties of a Mixture of Three- and Four-Branched Star Polystyrenes

Concentration Dependence of Viscoelastic Properties of a Mixture of Three- and Four-Branched Star Polystyrenes

Effect of polar solvents on dynamic moduli of concentrated solutions of polyethylacrylate

Extensional and Fractural Properties of Concentrated Solutions of Monodisperse Polystyrene at Elevated Temperatures

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