Solute diffusion in swollen membranes VII. Diffusion in semicrystalline networks

Harland, Ronald S.; Peppas, Nicholas A.

doi:10.1007/bf01410578

Cited by 55 publications

(18 citation statements)

References 32 publications

(30 reference statements)

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“…36 It has been shown by Harland and Peppas 37 that the value of is equal to 3.0 for the diffusion of small molecules through semicrystalline polymers, unless the volume fraction of the crystals is very low. In our studies, we have assumed ϭ1.0 when 2c Յ 0.05 and ϭ 3.0 when 2c Ͼ 0.05.…”

Section: Mathematical Modelingmentioning

confidence: 98%

Understanding isothermal semicrystalline polymer drying: Mathematical models and experimental characterization

Ngui

Mallapragada

1998

J. Polym. Sci. B Polym. Phys.

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Section: Mathematical Modelingmentioning

confidence: 98%

Understanding isothermal semicrystalline polymer drying: Mathematical models and experimental characterization

Ngui

Mallapragada

1998

J. Polym. Sci. B Polym. Phys.

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“…[34,35] In this study, the gel content measurement is used to study the kinetics of the condensation step of EPR-g-VTMS in the presence of sulfonic acid compounds. Figure 5 shows the temporal changes of gel content in EPR-g-VTMS system containing sulfonic acid observed at three different temperatures.…”

Section: Condensation Kinetics Of Epr-g-vtms Evaluated By Gel Fractiomentioning

confidence: 99%

The utility of sulfonic acid catalysts for silane water-crosslinked network formation in the ethylene–propylene copolymer system

Adachi

Hirano²

2008

J Sol-Gel Sci Technol

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Catalytic effects of Brönsted acid on the early kinetics of water-crosslinking reaction in the vinyltrimethoxysilane-grafted ethylene-propylene copolymer (EPR-g-VTMS) system were investigated by means of an attenuated total reflectance-Fourier transform infrared (ATR-FTIR) technique and gel fraction measurements. Four sulfonic acids with different substituent, including methanesulfonic acid (C1SO 3 H), 1-propanesulfonic acid (C3SO 3 H), 1-pentanesulfonic acid (C5SO 3 H), and dodecylbenzenesulfonic acid (C12PhSO 3 H), were selected to examine the progress and effect of progressive changes in the silane watercrosslinked network structure in comparison with a primary amine (n-octadecylamine, Lewis base). From the kinetic analysis using Arrhenius equation, we found that the frequency factors for both hydrolysis (ATR-FTIR) and condensation step (gel content) of EPR-g-VTMS decreased in the order of C1SO 3 H > C3SO 3 H > C5SO 3 H > C12PhSO 3 H, while the activation energy values for each reaction did not differ significantly.These relationships can be explained mainly on the basis of the diffusion factors of the sulfonic acids in EPRg-VTMS system. Moreover, the stress-strain curve comparison between water-crosslinked EPR-g-VTMS samples containing sulfonic acid and amine compound clearly indicated the difference in their tensile properties as a result of the catalyst variation; the use of sulfonic acid as water-crosslinking catalyst eventually achieves to the soft and tough water-crosslinked EPR-g-VTMS, while the hard and strong one was produced using amine catalyst. Not only the catalytic activity but also the type of the catalyst has eventually significant effects upon the physical properties of the water-crosslinked EPR-g-VTMS.3/32

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“…In semicrystalline polymers, solvent must follow tortuous paths through the amorphous portion of the polymer to get around the crystals in the polymer. Harland and Peppas [31] have shown that the value of t is equal to 3.0 for diffusion of small molecules through semicrystalline polymer, unless the volume fraction of crystals is very small. In our work, we assume that t is equal to 3.0 when v is greater than 0.05, otherwise, the effect of tortuosity can be neglected, and t is equal to 1.0.…”

Section: Mathematical Modelingmentioning

confidence: 99%

Drying of semicrystalline polymers: mathematical modeling and experimental characterization of poly(vinyl alcohol) films

Wong

Altınkaya

Mallapragada

2004

Polymer

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A mathematical model was developed to predict the drying mechanism of semicrystalline polymers involving multiple solvents. Since drying of semicrystalline polymers can be accompanied by changes in polymer degree of crystallinity, the model integrates crystallization kinetics and the Vrentas -Duda diffusion model to provide a better understanding of the mechanism. The model considers the effect of external conditions such as temperature, film shrinkage and diffusion and evaporation of multiple solvents during drying. Poly(vinyl alcohol) (PVA)/water/methanol was chosen as a test system. The drying kinetics of PVA films swollen in water and methanol were investigated using gravimetric techniques. The model predicts that higher temperatures, lower film thicknesses and lower methanol to water ratios increase the drying rate. The model predictions were compared with experimental data and showed good agreement. q

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Solute diffusion in swollen membranes VII. Diffusion in semicrystalline networks

Cited by 55 publications

References 32 publications

Understanding isothermal semicrystalline polymer drying: Mathematical models and experimental characterization

Understanding isothermal semicrystalline polymer drying: Mathematical models and experimental characterization

The utility of sulfonic acid catalysts for silane water-crosslinked network formation in the ethylene–propylene copolymer system

Drying of semicrystalline polymers: mathematical modeling and experimental characterization of poly(vinyl alcohol) films

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