An investigation of the structure of micelles formed by a polystyrene-b-poly(ethylene/propylene) block copolymer in paraffinic solvents using 1H and 13C-nuclear magnetic resonance
✍ Scribed by Francoise Candau; F. Heatley; C. Price; Rita B. Stubbersfield
- Publisher
- Elsevier Science
- Year
- 1984
- Tongue
- English
- Weight
- 811 KB
- Volume
- 20
- Category
- Article
- ISSN
- 0014-3057
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✦ Synopsis
The dynamic structure of micelles formed by a polystyrene-b-poly(ethylene/propylene) block copolymer in paraffinic solvents has been studied by electron microscopy, photon correlation spectroscopy and LH and 13C-nuclear magnetic resonance. In n-octane below 50 °, the polystyrene core has two components, a "rigid" component exhibiting the same NMR linewidth as bulk glassy polystyrene and a "mobile" component attributed to a plasticised surface layer. The "rigid" component undergoes a sharp linewidth transition at 50 attributed to segmental motions. In n-octane, the micelles dissociate significantly above 8if'. In higher alkanes, the dissociation occurs at increasing temperature with increasing solvent molecular weight.