CCXXXIV.—Molecular volumes at absolute zero. Part II. Zero volumes and chemical composition

Sugden, Samuel

doi:10.1039/jr9270001786

Cited by 90 publications

(47 citation statements)

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“…14 Wide-angle X-ray diffraction (WAXD) measurements were performed at room temperature on a D/Max-B X-ray diffractometer using Cu KR radiation at a wavelength of 1.54 Å (40 kV, 15 mA). The scanning rate was 2°/min over a range of 2θ ) 5-40°.…”

Section: Methodsmentioning

confidence: 99%

Gas and Water Vapor Transport through a Series of Novel Poly(aryl ether sulfone) Membranes

Wang

Chen

2001

Macromolecules

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The permeation behavior of water vapor, H2, CO2, O2, N2, and CH4 gases in a series of novel poly(aryl ether sulfone)s has been examined over a temperature range of 30-100°C. These polymers include four alkyl-substituted cardo poly(aryl ether sulfone)s and four intermolecular interaction enhanced poly(aryl ether sulfone)s. Their water vapor and gas transport properties were compared to the unmodified cardo poly(aryl ether sulfone) (PES-C). It was found that the bulky alkyl substituents on the phenylene rings were advantageous for gas permeability, while the intermolecular hydrogen bonds and ionic bonds resulted in a considerable increase in gas permselectivity. The causes of the trend were interpreted according to free volume, interchain distance, and glass transition temperature, together with the respective contribution of gas solubility and diffusivity to the overall permeability. Of interest was the observation that IMPES-L, which simultaneously bears bulky isopropyl substituent and pendant carboxylic groups, displayed 377% higher O 2 permeability and 5.3% higher O2/N2 permselectivity than PES-C. Furthermore, sodium salt form PES-Na + and potassium salt form PES-K + exhibited water vapor permeability twice as high as PES-C and H2O/N2 selectivity in 10 5 order of magnitude.

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Section: Methodsmentioning

confidence: 99%

Gas and Water Vapor Transport through a Series of Novel Poly(aryl ether sulfone) Membranes

Wang

Chen

2001

Macromolecules

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“…[93] The values of V Ã A are calculated using the group contribution method of Sugden. [104,105] Table A1. Parameters for diffusion coefficients of the non-macromolecules in the reaction system (A ¼ 1,. .…”

Section: Appendix Amentioning

confidence: 98%

“…Parameters for diffusion coefficients of the non-macromolecules in the reaction system (A ¼ 1,. . .,6); [92,93,104,105] Equation (A3). On the other hand, for the self-diffusion coefficient of a macromolecule with chain length i, a distinction has to be made between the polymer molecules and the macroradicals.…”

Section: Appendix Amentioning

confidence: 98%

Kinetic Modeling as a Tool to Understand and Improve the Nitroxide Mediated Polymerization of Styrene

Bentein

D’hooge

Reyniers

et al. 2011

Macro Theory & Simulations

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Kinetic modeling is used to obtain insight in the complex interplay between reaction rates and obtained polymer properties in the SG1 and the TEMPO mediated bulk polymerization of styrene at 396 K. The increase of the viscosity during NMP is accounted for. At higher targeted chain lengths, chain transfer to dimer and transfer from nitroxide to dimer are shown to cause the experimentally observed reduced control over the average polymer properties and to result in a clear fronting of the polymer chain length distribution. The potential of kinetic modeling to design tailor‐made synthesis strategies is illustrated. Simulations indicate that careful control of the polymerization conditions allows to obtain an important improvement of the polymer properties. The approach is also applicable for NMP mediated by other alkoxyamines/nitroxides and allows to expand the application range of NMP for styrene polymerization in particular to synthesize complex polymer architectures by assembly of functionalized polymers. magnified image

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“…Molar volumes at 0 K can be estimated using group contribution methods developed by Sugden (1927) and Biltz (1934). These methods were summarized by Haward (1970) and are reproduced in Table 1.…”

Section: P; and Pzmentioning

confidence: 99%

Predicting polymer/solvent diffusion coefficients using free‐volume theory

1992

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The VrentadDuda free-volume diffusion model accurately correlates polymer/ solvent diffusion coefficients over wide ranges of concentration and temperature. Currently the model is semipredictive: limited diffusion data are required to estimate model parameters that can then be used to predict diffusion coefficient behavior over sundry conditions. In this work, we present methods for estimating all of the model parameters without any diffusion data and examine the accuracy of the resulting diffusion coefficient predictions. This is the only technique known that predicts polymer/solvent diffusion behavior without any use of any diffusion data.

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CCXXXIV.—Molecular volumes at absolute zero. Part II. Zero volumes and chemical composition

Cited by 90 publications

References 0 publications

Gas and Water Vapor Transport through a Series of Novel Poly(aryl ether sulfone) Membranes

Gas and Water Vapor Transport through a Series of Novel Poly(aryl ether sulfone) Membranes

Kinetic Modeling as a Tool to Understand and Improve the Nitroxide Mediated Polymerization of Styrene

Predicting polymer/solvent diffusion coefficients using free‐volume theory

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