Diffusion coefficients of polyamidoamine cascade polymers (PAMAMs) were measured in aqueous solutions by dynamic light scattering and, after labeling with fluorescein isothiocyanate, by fluorescence photobleaching recovery. The dynamic light scattering results depended weakly on pH at a high salt co
Light Scattering Studies on Ternary Polymer Blend Solutions Comprising Poly(hydroxybutyrate)
✍ Scribed by Melinda J. K. Chee; Claudia Kummerlöwe; Manfred D. Lechner; Hans-Werner Kammer
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 141 KB
- Volume
- 205
- Category
- Article
- ISSN
- 1022-1352
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✦ Synopsis
Abstract
Summary: We report on light scattering studies of polymer blend solutions in trifluoroethanol (TFE). The polymer blends comprised poly(3‐hydroxybutyrate) (PHB) in combination with poly(ethylene oxide) (PEO) and poly(ε‐caprolactone) (PCL). PHBs of two different molecular masses were used. Relevant quantities were obtained from Zimm plots. All quantities display non‐linear dependencies on blend composition. For the blend system with PEO and PHB of lower molecular mass, we observed a negative excess of the second virial coefficient, which is indicative of the miscibility of the constituents. The opposite is observed for blends with PCL. The situation changes in blends with PEO and PHB of sufficiently high molecular mass. It turns out that PEO is only miscible with PHB of high molecular mass if it is the major component. This can be concluded from both light scattering and viscosity results.
Apparent molecular mass as a function of blend composition for PEO/PHB(1) and PCL/PHB(1) solutions in TFE at 25 °C.
imageApparent molecular mass as a function of blend composition for PEO/PHB(1) and PCL/PHB(1) solutions in TFE at 25 °C.
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