Finite difference modeling of the gas transport process in glassy polymers

Brolly, J. B.; Bower, D. I.; Ward, I. M.

doi:10.1002/(sici)1099-0488(199603)34:4<761::aid-polb17>3.0.co;2-f

Cited by 5 publications

(5 citation statements)

References 9 publications

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“…The relationship between volume fraction of crystallinity and linear crystallinity is expressed as V = , where is the fraction of the total volume of the sample occupied by stacks of lamellae [51]. Using the densities of the crystalline ( = 1.445 g/cm 3 ) and amorphous ( = 1.331 g/cm 3 ) phases for PET [52], the volume fraction crystallinity ( V = ) was transformed into mass fraction of crystallinity , according to Swam equation [53]:…”

Section: Characterization Techniques the Inherent Viscosity [ ]mentioning

confidence: 99%

Oxygen Barrier Properties and Melt Crystallization Behavior of Poly(ethylene terephthalate)/Graphene Oxide Nanocomposites

Szymczyk

Paszkiewicz

Pawelec

et al. 2015

Journal of Nanomaterials

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Poly(ethylene terephthalate) nanocomposites with low loading (0.1–0.5 wt%) of graphene oxide (GO) have been prepared by usingin situpolymerization method. TEM study of nanocomposites morphology has shown uniform distribution of highly exfoliated graphene oxide nanoplatelets in PET matrix. Investigations of oxygen permeability of amorphous films of nanocomposites showed that the nanocomposites had better oxygen barrier properties than the neat PET. The improvement of oxygen permeability for PET nanocomposite films over the neat PET is approximately factors of 2–3.3. DSC study on the nonisothermal crystallization behaviors proves that GO acts as a nucleating agent to accelerate the crystallization of PET matrix. The evolution of the lamellar nanostructure of nanocomposite and neat PET was monitored by SAXS during nonisothermal crystallization from the melt. It was found that unfilled PET and nanocomposite with the highest concentration of GO (0.5 wt%) showed almost similar values of the long period (L=11.4 nm for neat PET andL=11.5 nm for PET/0.5GO).

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Section: Characterization Techniques the Inherent Viscosity [ ]mentioning

confidence: 99%

Oxygen Barrier Properties and Melt Crystallization Behavior of Poly(ethylene terephthalate)/Graphene Oxide Nanocomposites

Szymczyk

Paszkiewicz

Pawelec

et al. 2015

Journal of Nanomaterials

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“…Intermediate values of n suggest a combination of these two mechanisms. On the other hand, the discrepancies between the experimental sorption and desorption curves are representative of different kinetics and then, of a concentration-dependent diffusion coefficient (Crank, 1975;Brolly et al, 1996aBrolly et al, , 1996b). …”

Section: Mechanisms Of Diffusionmentioning

confidence: 99%

“…According to them, the dualmode sorption model is based on a correct mathematical description but on invalid physical assumptions, which are the existence of two different populations of diffusing molecules and the absence of gas-polymer interactions. Also, let us quote Brolly et al (1996aBrolly et al ( , 1996b who determined experimentally the effective coefficients of solubility and diffusion of CO 2 in PET and in PEN, at room temperature, the pressure varying from 0.0125 to 0.5 MPa. These authors used the finite difference modelling for obtaining the parameters relative to the two models and so the variations of the effective diffusion coefficient with the penetrant concentration.…”

Section: Comparison Of These Two Modelsmentioning

confidence: 99%

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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“…The desorption experiments, Figure 2 (right) and Table 1, show remarkably large effective diffusivities, particularly after equilibration at the higher pressures. However, if the local diffusivity was to decrease during desorption instantaneously to the value from eq 17 corresponding to the local C D , then desorption would be slower than sorption 14, 26. In the specimen's skin region, where C D is smallest and ∂ C D /∂ X is largest, D D would be the least; a layer of low permeability near the surface would hinder the loss of vapor from the interior.…”

Section: Resultsmentioning

confidence: 99%

“…Similar observations of the effect of pressure on the diffusion coefficient were made by Kumar and Stolarczuk24 for the CO 2 ‐poly(ethylene terephthalate) system and by Kumar and Weller25 for the CO 2 ‐polycarbonate system. Brolly et al26 investigated the variation in the diffusion coefficients with penetrant pressure for the CO 2 ‐poly(ethylene terephthalate) and CO 2 ‐poly(ethylene naphthalate) systems. They found a significant rise in the effective diffusion coefficient as a result of an increase in pressure.…”

Section: Resultsmentioning

confidence: 99%

Sorption and diffusion of carbon dioxide in wood‐fiber/polystyrene composites

Doroudiani

Chaffey

Kortschot

2002

J Polym Sci B Polym Phys

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In this study, sorption and diffusion of carbon dioxide (CO 2 ) in wood-fiber/ polystyrene composites were investigated. The effects of gas pressure and fiber content on the solubility and diffusion coefficients were evaluated. A statistical analysis indicated that pressure is more important than fiber content in determining the solubility and diffusivity of CO 2 . An increase in saturation pressure causes an increase in the solubility and diffusion coefficients, whereas inclusion of the fibers decreases both of these properties. Models were developed to predict the uptake and diffusion coefficients of CO 2 in the composite samples as functions of pressure and fiber content. A theoretical model based on Henry's law and the Langmuir equation compared favorably to the experimental data for CO 2 solubility. This dual mode model also described both the transient sorption and desorption data, but only if the concentration-dependent value of diffusivity was treated as a history-dependent parameter.

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Finite difference modeling of the gas transport process in glassy polymers

Cited by 5 publications

References 9 publications

Oxygen Barrier Properties and Melt Crystallization Behavior of Poly(ethylene terephthalate)/Graphene Oxide Nanocomposites

Oxygen Barrier Properties and Melt Crystallization Behavior of Poly(ethylene terephthalate)/Graphene Oxide Nanocomposites

Transport Properdines of Gases in Polymers: Bibliographic Review

Sorption and diffusion of carbon dioxide in wood‐fiber/polystyrene composites

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