Concentration-dependent viscoelastic scaling models for polydimethysiloxane melts with dissolved carbon dioxide

Gerhardt, Linda J.; Garg, Ashok; Manke, Charles W.; Gulari, Esin

doi:10.1002/(sici)1099-0488(199808)36:11<1911::aid-polb12>3.0.co;2-a

Cited by 57 publications

(74 citation statements)

References 1 publication

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“…Reviewing the literature for polymer processing and macromolecules, the Sanchez-Lacombe (S-L), and Panayiotou-Vera (P-V) equations yield fairly accurate predictions for pure polymer melt and diluted melt polymer solutions. 83,84,85,86,87 Both use equilibrium chemical potentials in the melt and gas phases to correlate solubility to the pure phase through a binary interaction parameter. The models and modeling techniques may possibly be extended to pitch as well.…”

Section: Background On Pitch Foamsupporting

confidence: 89%

Development of Continuous Solvent Extraction Processes for Coal Derived Carbon Products

Dadyburjor¹,

Heavner²,

Katakdaunde³

et al. 2006

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Section: Background On Pitch Foamsupporting

confidence: 89%

Development of Continuous Solvent Extraction Processes for Coal Derived Carbon Products

Dadyburjor¹,

Heavner²,

Katakdaunde³

et al. 2006

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“…The effects of CO 2 dissolution on viscoelastic properties were studied with capillary rheometers or extruders; for example, the shear rate dependence of viscosity was examined in the thinning regime. 1,2) These studies suggested that the dissolved CO 2 enhances the polymer chain motion (and effectively increase a distance from the glass transition point.) However, details of this effect on the linear viscoelastic relaxation and the equilibrium chain dynamics were not clarified.…”

Section: Introductionmentioning

confidence: 99%

Dielectric Behavior of cis-Polyisoprene in Carbon Dioxide under High Pressure

Inoue

Watanabe

Kihara

et al. 2007

J. Soc. Rheol., Jpn

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Dielectric measurement was conducted for cis-polyisoprene (PIP) in carbon dioxide (CO 2 ) at high pressures. CO 2 is dissolved in PIP more with increasing pressure, and this dissolution is expected to affect the chain dynamics. In our experimental window, the PIP chains having type-A dipoles parallel along their backbone exhibited the dielectric dispersion reflecting their global motion. This dispersion shifted to higher frequencies with increasing CO 2 pressure. Time -CO 2 pressure superposition was found to hold well, which suggests that the global motion of the chain is accelerated by CO 2 without any heterogeneity in space and along the chain backbone. The vertical shift factor (intensity shift factor) for this superposition gave the CO 2 concentration in PIP. The plasticizing capability of CO 2 evaluated from the horizontal shift factor (frequency shift factor) was found to be a little larger than that of tetradecane in the same range of concentration. No peculiarity was found for plasticizing ability of CO 2 even in the supercritical state (at a pressure of 10 MPa).

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“…Several research groups have already demonstrated the utility of pressure-tuning supercritical carbon dioxide (scCO 2 ) in synthesis, [2][3][4][5] foaming, 6,7 and rheological modification. [8][9][10][11][12] All of the specific processes tend to exploit the swelling and plasticization of the polymer, which results from the inclusion of a large amount of the SCF into a polymer matrix under pressure.…”

Section: Introductionmentioning

confidence: 99%

Carbon Dioxide-Induced Swelling of Poly(dimethylsiloxane)

1999

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A new experimental device is used to monitor in situ the swelling behavior of poly-(dimethylsiloxane) melts in contact with supercritical carbon dioxide. The effects of pressure, temperature, and sample molecular weight on the kinetics and extent of swelling are examined using this experimental technique. The swelling kinetics of all polymer samples exhibit two distinct regimes: an initial region of large swelling in which the diffusion of CO 2 into the polymer follow Fickian behavior and a subsequent region of small volume increase asymptotic to an equilibrium swelling value. Diffusion coefficients of CO2, obtained from the initial swelling kinetics data, are found to be relatively insensitive to pressure, increase with temperature, and decrease with polymer molecular weight with the latter exhibiting a power-law dependence with an exponent of ∼-2. The extent of swelling increases with both pressure and molecular weight but exhibits different trends with temperature depending on system pressure. For pressures below 15 MPa the extent of swelling decreases monotonically with temperature. However, for pressure above this threshold, a maximum in swelling is observed with temperature increments. The maximum with temperature is thought to be a result of large variations in the physical properties of CO 2 near its critical point. The results of equilibrium swelling have been modeled using the Sanchez-Lacombe equation of state and found to be in good agreement with the thermodynamic theory.

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Concentration-dependent viscoelastic scaling models for polydimethysiloxane melts with dissolved carbon dioxide

Cited by 57 publications

References 1 publication

Development of Continuous Solvent Extraction Processes for Coal Derived Carbon Products

Development of Continuous Solvent Extraction Processes for Coal Derived Carbon Products

Dielectric Behavior of cis-Polyisoprene in Carbon Dioxide under High Pressure

Carbon Dioxide-Induced Swelling of Poly(dimethylsiloxane)

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