Gas Transport and Cooperative Main-Chain Motions in Glassy Polymers

Raucher, Daniel; Sefcik, M. D.

doi:10.1021/bk-1983-0223.ch005

Cited by 22 publications

(12 citation statements)

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“…we shall detail the dual-mode sorption model, the most usually used (Barrer et al, 1958), then the gas-polymer matrix model Raucher and Sefcik, 1983a).…”

Section: Glassy Polymers (T < T G )mentioning

confidence: 99%

“…Initially, it was assumed that the population of Langmuir was completely immobilised and did not participate in the transport (Vieth and Sladek, 1965;Raucher and Sefcik, 1983a) what implied a constant permeability coefficient. Experimentally, permeability measurements have shown evidence of a decrease of the permeability coefficient with the upstream gas pressure: let us quote, for instance, the case of CO 2 in polycarbonate at 35°C .…”

Section: Dual-mode Sorption Modelmentioning

confidence: 99%

“…If one supposes a linear diminution of T g with concentration (Raucher and Sefcik, 1983a), Equation (26) becomes:…”

Section: Gas-polymer Matrix Modelmentioning

confidence: 99%

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Transport Properdines of Gases in Polymers: Bibliographic Review

Klopffer

Flaconnèche

2001

Oil & Gas Science and Technology - Rev. IFP

253

196

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Résumé -Transport de molécules gazeuses dans les polymères : revue bibliographique -Après quelques rappels concernant les lois classiques des phénomènes de transport, cet article, purement bibliographique, présente les différents modèles théoriques proposés pour décrire le mécanisme de transport d'espèces chimiques dans les polymères par diffusion moléculaire. Il s'appuiera ensuite sur de nombreuses études menées antérieurement, pour montrer que la perméabilité des gaz (ou vapeurs organiques) dépend fortement de la structure du polymère (cristallinité, histoire thermomécanique), de la taille et de la nature du pénétrant ainsi que des conditions de température et de pression.Mots-clés : polymère, gaz, perméabilité, diffusion, solubilité. Abstract -Transport Properties of Gases in

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“…we shall detail the dual-mode sorption model, the most usually used (Barrer et al, 1958), then the gas-polymer matrix model Raucher and Sefcik, 1983a).…”

Section: Glassy Polymers (T < T G )mentioning

confidence: 99%

Section: Dual-mode Sorption Modelmentioning

confidence: 99%

See 1 more Smart Citation

Transport Properdines of Gases in Polymers: Bibliographic Review

Klopffer

Flaconnèche

2001

Oil & Gas Science and Technology - Rev. IFP

253

196

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“…For a simplified discusergy of the diffusion. 9,10 The larger the gas molesion of this behavior the idea of a solubility-type Figure 7 Crosslink density (number of net meshes per carbon atom) of the plasma polymers calculated by Figure 6 Molar oxygen-to-carbon ratio from quantitative elemental analysis of the plasma polymers as a X-ray analysis and quantitative elemental analysis as a function of hexafluoroethane-to-hydrogen volume rafunction of hexafluoroethane-to-hydrogen volume ratio in the feed gas.…”

Section: Morphology Of Plasma Polymer Layersmentioning

confidence: 99%

“…9,10 tirely different from conventional polymerization reactions. [3][4][5][6] In the first reaction step, the moleThis paper deals with fluorine-containing plasma polymers produced from different hexcules of an organic gas exposed to a glow discharge undergo electron impact and subsequent fragafluoroethane/hydrogen mixtures and their applicability in membrane-based air separation.…”

Section: Introductionmentioning

confidence: 99%

Plasma polymer membranes from hexafluoroethane/hydrogen mixtures for separation of oxygen and nitrogen

Huber¹,

Springer²

1997

J. Appl. Polym. Sci.

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Thin plasma polymer layers were produced employing feed mixtures of hexafluoroethane and hydrogen in an rf parallel-plate reactor. The layers are intended for use in membrane-based separation of oxygen and nitrogen. The hexafluoroethaneto-hydrogen mixture ratio was varied over a wide range, whereas all other process parameters (power, pressure, substrate temperature, and total gas flow) were held constant. The plasma polymers were examined by scanning electron microscopy, Xray analysis, quantitative elemental analysis, and X-ray photoelectron spectroscopy. Permeability coefficients of oxygen and nitrogen and selectivities of the pure gases were determined. Pinhole-free plasma polymer films containing different amounts of fluorine, carbon, and hydrogen were formed. The distributions of fluorine and hydrogen in the products reflect their distributions in the feed gas. Traces of oxygen in some of the polymers are explained by the reaction of trapped radicals with atmospheric oxygen on the samples' exposure to air. Fluorine-containing carbon moieties such as CF 3 , CF 2 , and CF, and carbon moieties with fluorine atoms exclusively in secondary positions are present. A method of calculating crosslink density using the analytical data is described. The oxygen permeability coefficient and the selectivity of the plasma polymers increase as the hexafluoroethane content of the feed gas is raised. This behavior is attributed to growing solubility selectivity as a result of the rising fluorine content of the polymers. Maximum selectivity amounts to 3.4 at an oxygen permeability coefficient of 21

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