Physical aging of thin glassy polymer films monitored by gas permeability

Yu, Hao; Paul, Donald R

doi:10.1016/j.polymer.2004.10.019

Cited by 315 publications

(374 citation statements)

References 88 publications

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“…This aging process is of great interest in applications where the associated property evolution can be a matter of practical concern in the end-use of the materials. For example, separations processes frequently involve polymer membranes that can exhibit significant aging effects on their permeability, 5 and this process has great significance for the mechanical properties of influencing end-use applications of diverse structural polymeric and glassy materials broadly. 6 a) E-mail: jack.douglas@nist.gov.…”

Section: Introductionmentioning

confidence: 99%

Evolution of collective motion in a model glass-forming liquid during physical aging

Shavit

Douglas

Riggleman

2013

The Journal of Chemical Physics

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At temperatures moderately below their glass transition temperature, the properties of many glassforming materials can evolve slowly with time in a process known as physical aging whereby the thermodynamic, mechanical, and dynamic properties all drift towards their equilibrium values. In this work, we study the evolution of the thermodynamic and dynamic properties during physical aging for a model polymer glass. Specifically, we test the relationship between an estimate of the size of the cooperative rearrangements taking the form of strings and the effective structural relaxation time predicted by the Adam-Gibbs relationship for both an equilibrium supercooled liquid and the same fluid undergoing physical aging towards equilibrium after a series of temperature jumps. We find that there is apparently a close correlation between a structural feature of the fluid, the size of the string-like rearrangements, and the structural relaxation time, although the relationship for the aging fluid appears to be distinct from that of the fluid at equilibrium.

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Section: Introductionmentioning

confidence: 99%

Evolution of collective motion in a model glass-forming liquid during physical aging

Shavit

Douglas

Riggleman

2013

The Journal of Chemical Physics

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“…Therefore, the physical and chemical properties of glassy polymers are particularly influenced by thermal history [16][17][18][19][20][21][22][23][24][25] and physical aging [26][27][28][29][30][31][32], which can substantially change the material response to the external stresses and, what is of particular importance in the present discussion, can definitely affect its permeation properties.…”

Section: Introductionmentioning

confidence: 93%

“…In addition, the aging phenomenon has been demonstrated to be thickness-dependent, especially if ranges of film thicknesses of 1 lm or lower are explored. To maximize the membrane productivity, thin selective layers (thickness < 1 lm) must be coated on porous supports, but thinner films undergo a faster aging rate, which can be up to an order of magnitude more rapid than in the thicker layers [26][27][28][29][30].…”

Section: Introductionmentioning

confidence: 99%

“…In the past, many studies have been presented on the effect of physical aging on polymeric membranes [26][27][28][29][30][31][32] and in parallel some models have also been proposed for its description [15,28,34,35]. On the other hand, the influence of thermal treatment on transport properties requires a careful analysis in order to consider the different features that can be involved, as for instance, rearrangements of the macromolecules and their possible stiffening or softening, as well as the changes in polymer density.…”

Section: Introductionmentioning

confidence: 99%

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Effects of Thermal Treatment and Physical Aging on the Gas Transport Properties in Matrimid^®

Ansaloni

Minelli

Baschetti

et al. 2014

Oil Gas Sci. Technol. – Rev. IFP Energies nouvelles

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-Carbon dioxide and methane transport in a commercial polyimide, Matrimid 5218 Ò , has been characterized in order to evaluate the effect of membrane thermal treatment and physical aging on its potentialities for CO 2 /CH 4 separation. In particular, CO 2 and CH 4 permeabilities and diffusion coefficients were measured at three different temperatures (35, 45 and 55°C) in films pretreated at 50, 100, 150 and 200°C, respectively. The performances of each sample were examined for a period of more than 3 000 hours. Permeability and diffusivity values for both penetrants showed a marked decrease with increasing the pretreatment temperature up to 150°C and remained, then, substantially unchanged for specimens pretreated at the highest temperature. Interestingly, the samples characterized by the higher flux after film formation also showed a faster aging phenomenon, leading to a 25% decrease of CO 2 permeability in the period inspected. Conversely, the samples pretreated at temperatures of 150°C, or higher, displayed very stable transport properties for the entire duration of the monitoring campaign. At the end of the aging period considered, the differences among samples were definitely reduced, suggesting that the initial behaviors are related to different polymer structures induced by pretreatment, which slowly evolve in time towards more similar and more stable configurations. Such aging rearrangements affect both CO 2 and CH 4 permeability in a similar way, so that no significant changes were observed for selectivity, which showed only a slight increment by increasing the temperature of the thermal treatment or the duration of the aging period. 150°C ont affiche´des proprie´te´s de transport tre`s stables pendant toute la dure´e des mesures. Par conse´quent, a`la fin de l'e´tude, les diffe´rences entre les e´chantillons ont e´te´nettement re´duites, ce qui sugge`re que la structure initiale pourrait eˆtre due a`des structures polyme´riques diffe´rentes, induites par un pre´traitement, qui e´voluent lentement avec le temps vers des configurations plus semblables et plus stables. Il est important de remarquer qu'un tel re´arrangement a affected e la meˆme manie`re la perme´abilite´au CO 2 et celle au CH 4 . Nous n'observons donc pas de changements significatifs en ce qui concerne la se´lectivite´qui a montre´seulement une le´ge`re hausse lorsque l'on augmente la tempe´rature du traitement thermique ou le temps de vieillissement.

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“…These may cause polymer chains to orient in preferential directions. The preferred orientations of polymer chains induce internal stresses in the material that in turn can affect the permeability and the selectivity [26]. For many polymers, the heating above the glass transition temperature and subsequent thermal quenching remove the non-equilibrium characteristics.…”

Section: Introductionmentioning

confidence: 99%

Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

2015

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The thickness, the refractive index, and the optical anisotropy of thin sulfonated poly(ether ether ketone) films, prepared by spin-coating or solvent deposition, have been investigated with spectroscopic ellipsometry. For not too high polymer concentrations (B5 wt%) and not too low spin speeds (C2000 rpm), the thicknesses of the films agree well with the scaling predicted by the model of Meyerhofer, when methanol or ethanol are used as solvent. The films exhibit uniaxial optical anisotropy with a higher in-plane refractive index, indicating a preferred orientation of the polymer chains in this in-plane direction. The radial shear forces that occur during the spin-coating process do not affect the refractive index and the extent of anisotropy. The anisotropy is due to internal stresses within the thin confined polymer film that are associated with the preferred orientations of the polymer chains. The internal stresses are reduced in the presence of a plasticizer, such as water or an organic solvent, and increase to their original value upon removal of such a plasticizer.

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Physical aging of thin glassy polymer films monitored by gas permeability

Cited by 315 publications

References 88 publications

Evolution of collective motion in a model glass-forming liquid during physical aging

Evolution of collective motion in a model glass-forming liquid during physical aging

Effects of Thermal Treatment and Physical Aging on the Gas Transport Properties in Matrimid^®

Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

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Physical aging of thin glassy polymer films monitored by gas permeability

Cited by 315 publications

References 88 publications

Evolution of collective motion in a model glass-forming liquid during physical aging

Evolution of collective motion in a model glass-forming liquid during physical aging

Effects of Thermal Treatment and Physical Aging on the Gas Transport Properties in Matrimid®

Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

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Product

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Effects of Thermal Treatment and Physical Aging on the Gas Transport Properties in Matrimid^®