Modelling the sorption of water–ethanol mixtures in cross-linked ionic and neutral polymers

Tiihonen, Jari; Markkanen, Ismo; Kärki, Ari; Äänismaa, Päivi; Laatikainen, Markku; Paatero, Erkki

doi:10.1016/s0009-2509(02)00097-0

Cited by 8 publications

(4 citation statements)

References 24 publications

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“…The same disagreement was also encountered in the work of Mazzotti et al 9 using an alternative expression for the elasticity term capable of dealing with a non-Gaussian distribution of chain lengths, where again the fitted values exceeded the expected ones by a factor of more than 100. In order to overcome this problem, alternative models to describe the pressure changes within the resin at different degrees of swelling have been proposed recently, 17 taking into account the limited extensibility of strongly cross-linked resins.…”

Section: The Water-methanol Binary Systemmentioning

confidence: 99%

Sorptive and Catalytic Properties of Partially Sulfonated Resins

Lode

Freitas

Mazzotti

et al. 2004

Ind. Eng. Chem. Res.

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Sulfonic poly(styrene-co-divinylbenzene) ion-exchange resins are commonly employed as supported acid catalysts or as selective sorbents in a number of different applications. Using the reaction of acetic acid and methanol to form methyl acetate and water as a model system, the competitive sorption behavior of the corresponding nonreactive binary pairs was studied for macroporous, highly cross-linked resins of different acid loading. It was found that a reduction of the acid loading decreases the resins' selectivity toward the sorption of water and increases its affinity toward less polar species, e.g., methyl acetate. To describe the sorption behavior a phase equilibrium model based on the Flory-Huggins theory of polymer swelling was developed, taking into account the hydration of the acid sites upon the sorption of water. The ability of the model to represent the competitive sorption behavior as a function of the resin's acid loading has been demonstrated by comparison with various sets of experimental equilibrium data. Finally, initial work to characterize the catalytic performance for different degrees of sulfonation is presented, and conclusions toward the application of these resins as stationary phases for reactive chromatography are drawn.

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Section: The Water-methanol Binary Systemmentioning

confidence: 99%

Sorptive and Catalytic Properties of Partially Sulfonated Resins

Lode

Freitas

Mazzotti

et al. 2004

Ind. Eng. Chem. Res.

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“…This reduction in properties can be attributed to the high content of ethanol and the degradation of the epoxy in the presence of ethanol molecules. [ 19,58 ] This suggests that once a sample fractures, the process of epoxy degradation due to ethanol is almost complete at the sample saturation point.…”

Section: Resultsmentioning

confidence: 99%

Characterization of moisture absorption and flexural performance of functionalized graphene modified carbon fiber composites under low energy impact

et al. 2023

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Composite failure due to in‐service low energy impact damage and moisture absorption is a major risk for these materials within aerospace, automotive and other engineering sectors. Deterioration in post‐impact flexural properties, and the tendency of thermosets to absorb moisture are some of the few drawbacks of carbon fiber reinforced polymers (CFRPs). Adding graphene into the matrix is theorized to improve mechanical properties and reduce moisture uptake. This study evaluates the diffusion characteristics and flexural properties of carbon fiber/epoxy composites modified with NH2 functionalized graphene (CFRP/graphene nanoparticle [GNPs]) before and after impact under various environmental conditions. Adding GNPs to CFRP decreased the flexural strength and modulus by 24% and 25% respectively before impact. After impact, the flexural strength and modulus decreased by 7.4%–23.6% and 37%–67%, respectively. For both composites after undergoing impact, the residual strength and stiffness were considerably reduced due to delamination and transverse cracking. Samples with graphene inclusion experienced a slower rate of ethanol and water diffusion, for both unimpacted and impacted samples, by 46.4% and 44.8%, respectively. Moisture uptake also reduced the flexural properties of both composites. Scanning electron microscopy revealed good dispersion but poor bonding of graphene to the matrix, which is believed to be the reason for property reduction.

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“…Numerous expressions have been proposed to estimate the swelling pressure in cross-linked polymer resins. In this work, one derived from the three-chain model of elastic networks, ,, is used; see eq . K el is the elastic coefficient of the polymer and is correlated with the nominal divinylbenzene content (wt %) of the resin, that is, ξ DVB , according to eq .…”

Section: Methodsmentioning

confidence: 99%

Critical Assessment of the Thermodynamics in Acidic Resin-Catalyzed Esterifications

Lauwaert

Steene

Vermeir

et al. 2020

Ind. Eng. Chem. Res.

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Resins are interesting catalysts for organic reactions, which are characterized by a remarkable swelling behavior upon exposure to liquids, typically resulting in selective sorption in the case of mixtures. Hence, when constructing kinetic models for reactions catalyzed by such resins, the component partitioning between the bulk liquid and polymer liquid and its effect on their thermodynamic activities have to be properly taken into account. A kinetic model is developed for acidic resin-catalyzed esterification, while comparing two scenarios for capturing the thermodynamics within the resin pores. For the specific case study on a single resin with a specific solvent, compensation effects between the calculated thermodynamic activities in the resin and the estimated rate coefficients render only minor performance differences between the two scenarios. Still, aiming at extending the scope toward other solvents and/or resins, it is deemed crucial to explicitly account for the resin's selective sorption and swelling behavior.

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Modelling the sorption of water–ethanol mixtures in cross-linked ionic and neutral polymers

Cited by 8 publications

References 24 publications

Sorptive and Catalytic Properties of Partially Sulfonated Resins

Sorptive and Catalytic Properties of Partially Sulfonated Resins

Characterization of moisture absorption and flexural performance of functionalized graphene modified carbon fiber composites under low energy impact

Critical Assessment of the Thermodynamics in Acidic Resin-Catalyzed Esterifications

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