Amorphous polystyrene-block-polybutadiene and crystallizable polystyrene-block-(hydrogenated polybutadiene) solutions in compressible near critical propane and propylene – Hydrogenation effects

Winoto, Winoto; Radosz, Maciej; Hong, Kunlun; Mays, Jimmy W.

doi:10.1016/j.jnoncrysol.2009.05.027

Cited by 8 publications

(4 citation statements)

References 19 publications

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“…Its mixtures with higher alkanes or other hydrocarbons do not change the nonpolar chemical nature of the mixture and as such have been of value in applications that involve polymer formation and modifications in dense fluids at high pressures. In this context, propane has been explored for solubilization and fractionation of polyethylene − or long chain hydrocarbons such as waxes up to 102 C-atoms , and polystyrene, , for solubilizing polyisoprene and ethylene-propylene copolymers, for miscibility and processing of polypropylene − and copolymers of ethylene with octene-1, for separation of polymer blends such as polyethylene and polystyrene into their components, for miscibility of poly(dodecyl methacrylate) or polybutadiene, for polymerization and foaming of poly(methyl methacrylate-co- ethylene glycol-dimethacrylate), for impregnation of modified polyethylene, for micellization of block copolymers of styrene with isoprene or butadiene, − or for polymerization of ethylene . Unlike propane, literature on the use of n -octane for miscibility and processing of polymers at high pressures is extremely limited.…”

Section: Introductionmentioning

confidence: 99%

Volumetric Properties of Propane, n-Octane, and Their Binary Mixtures at High Pressures

Milanesio

Hassler

Kiran

2013

Ind. Eng. Chem. Res.

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Density, isothermal compressibility, isobaric expansivity, thermal pressure coefficient, and excess volumes for binary mixtures of propane + n-octane are reported over a wide range of temperatures (from 320 to 440 K), and pressures (up to 400 bar) for mixture compositions with 0, 20.4, 42.4, 58.9, 79.7, and 100 wt % propane. Densities were determined using a fully computerized variable-volume view-cell system. A motorized pressure generator is used to bring about changes in the position of a movable piston in the cell at controlled and adjustable rates thereby bringing about changes in the internal volume and thus pressure. A long stroke-length linear variable differential transformer is used to continually monitor the position of the piston and thus the cell volume in real-time. Knowing the initial loading of the cell and the cell volume at any moment as pressure is altered permits generation of continuous density profiles along pressure scans in increasing (compression) or decreasing (decompression) direction of pressure at a given temperature. The density isotherms are readily correlated with polynomial equations and are used to generate the derived thermodynamic quantities such as the isothermal compressibility, isobaric expansivity, pressure coefficient, and excess volume. The results are discussed in terms of the effect of temperature, pressure and fluid composition for which there is no prior information in the open literature. In going from n-octane to propane, the data shows that compressibilities and expansivities increase, but the pressure coefficients tend to decrease. As examples, at 200 bar and 400 K, in going from n-octane to propane, values of compressibilities increase from about 2.0 × 10–4 to 1.0 × 10–3 bar–1; isobaric expansivities increase from about 1.0 × 10–3 to 2.5 × 10–3 K–1, whereas thermal pressure coefficients decrease from about 4 to 3 bar/K. The excess volumes become more negative with increasing propane content, and the mixture with about 80 mol % (or 60 wt %) propane showing the largest negative excess volume of about −6.5 cm3/mol.

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Section: Introductionmentioning

confidence: 99%

Volumetric Properties of Propane, n-Octane, and Their Binary Mixtures at High Pressures

Milanesio

Hassler

Kiran

2013

Ind. Eng. Chem. Res.

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“…The study of conformational properties (i.e., hydrodynamic radius) of polymers in supercritical fluids has been an area of active research. Some commonly used supercritical fluids (ScF) for polymers include carbon dioxide (CO 2 ),1–4 ethane (C2),1, 3, 5, 6 and propane (C3)1, 3, 5, 7–9 due to their relatively low‐critical temperatures and pressures. The solubility of polystyrene (PS) in these three supercritical fluids is well known 1, 5, 10.…”

Section: Introductionmentioning

confidence: 99%

Polystyrene/decahydronaphthalene/propane phase equilibria and polymer conformation properties from intrinsic viscosities

Cain

Haywood

Roberts

et al. 2011

J Polym Sci B Polym Phys

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The influence of dissolved propane (up to 31.2 wt %) on the phase equilibria of 5 wt % polystyrene (PS) dissolved in 66/34 wt % trans/cis‐decahydronaphthalene (DHN) was measured over the temperature range of 323–423 K. A suitable temperature, pressure, and propane composition operating space was defined to measure intrinsic viscosities of a single fluid phase. Intrinsic viscosities of PS in cosolvent mixtures of propane and trans/cis‐DHN were measured between 323 and 423 K and between 70 and 208 bar. The addition of propane to the isomeric mixture of DHN resulted in a decreased solvent quality for PS, causing a contraction of the PS coil. The most dramatic decrease in solvent quality with the addition of propane occurred at 323 K and 70 bar with approximately a 36% reduction in the viscometric radius with the addition of 45 mol % propane to DHN. At 423 K, the solvent quality was less sensitive to the addition of propane and only a 13% reduction in the viscometric radius was observed at 70 bar and 45 mol % propane in DHN. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011

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“…4 At a constant polymer concentration, both micellization temperature and pressure were found to fall around a decreasing micellar phase boundary curve in pressureÀ temperature coordinates, which lies above the copolymer cloudpoint curve and below the polystyrene cloud-point curve. That work also provided quantitative data on the effects of copolymer molecular weight, 5,6 block ratio, 6 crystallizability, 7 deuteration, 8 solvent, 6,7 and cloud pressure reduction 4À6,8 in micellar solutions relative to a hypothetical random solution estimated from statistical associating fluid theory. 9 However, we do not understand how the presence of a deliberately added core-philic solute can affect the micellization of a model styreneÀdiene block copolymer in a compressible alkane solvent, such as propane.…”

Section: ' Introductionmentioning

confidence: 99%

Decompression-Induced Encapsulation of Core-philic Solutes by Block Copolymer Micelles in Compressible Solutions: Polystyrene and Polystyrene-block-polybutadiene in Near-Critical Propane

Winoto

Radosz

2011

Macromolecules

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Pressure-tuned propane capacity and selectivity for polystyrene-block-polybutadiene allows for random molecular solutions at high pressures, micellar solutions at moderate pressures, and bulk phase separation at low pressures. While corona-philic homopolymer solutes primarily stay in solution when the micelles are formed, core-philic homopolymer solutes, such as polystyrene, are found to concentrate in and hence become encapsulated by the micelle core. If the concentration of such a block-sized polystyrene solute is in the right range, say up to 15 wt % on a solvent-free basis, it can produce an encapsulation peak on either the transmitted-light intensity trace or the scattered-light intensity trace, or both. Such encapsulation peaks can help detect the onset of micellization and encapsulation, especially when guided by a macromolecular model, such as statistical associating fluid theory (SAFT1), used to estimate the onset of bulk phase transitions in this work. A core-philic solute, free polystyrene in this case, does not alter the crucial micellization pressure or even the micellar cloud pressure, at which the micelles coalesce and precipitate from solution in bulk.

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Amorphous polystyrene-block-polybutadiene and crystallizable polystyrene-block-(hydrogenated polybutadiene) solutions in compressible near critical propane and propylene – Hydrogenation effects

Cited by 8 publications

References 19 publications

Volumetric Properties of Propane, n-Octane, and Their Binary Mixtures at High Pressures

Volumetric Properties of Propane, n-Octane, and Their Binary Mixtures at High Pressures

Polystyrene/decahydronaphthalene/propane phase equilibria and polymer conformation properties from intrinsic viscosities

Decompression-Induced Encapsulation of Core-philic Solutes by Block Copolymer Micelles in Compressible Solutions: Polystyrene and Polystyrene-block-polybutadiene in Near-Critical Propane

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