This article describes the rheological properties of certain poly(ethylene oxide)s dissolved in water-based solvents. The experimental results show that the rheological properties in aqueous solutions are significantly affected by the solvent properties, which have been changed by the use of ethanol
Aggregate formation in poly(ethylene oxide) solutions
β Scribed by Mohammad Saleem Khan
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 426 KB
- Volume
- 102
- Category
- Article
- ISSN
- 0021-8995
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β¦ Synopsis
Abstract
Static light scattering and viscosity measurements were performed on different molecular weight poly (ethylene oxide) to see the formation of aggregates in its dilute solutions. Viscosity measurements were carried out for PEO samples in water and methanol at 20β45Β°C and in chloroform at 20β30Β°C. Using Huggin's equation, the viscosity plots showed distinct upward curvature indicating the presence of aggregates in both PEO/H~2~O and PEO/CH~3~OH solutions The [Ξ·] values for PEO/H~2~O and PEO/CH~3~OH system were 2β4 times as large as observed for other linear flexible polymers in good solvents thus showing extensive coil swelling/aggregation. This is also apparent from the exponent a values of the MarkβHouwinkβSakurada equation. Light Scattering results using Zimm method showed that aggregation occurred in low molecular weight samples; however, in higher molecular weight samples there was a little evidence for aggregation both in water and methanol. Β© 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2578β2583, 2006
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The authors are indebted to Prof. E. Straube (Halle), Prof. K.-F. Arndt (Dresden) and Prof. J. Kressler (Merseburg) for helpful discussions concerning scattering measurements. Thanks to Chr. Sommer for support in static light scattering experiments.