Synthesis and Micellization Behavior of Polystyrene-b-Polydimethylsiloxane Block Copolymers
| Autor: | Ming-song Wu, 吳明松 |
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| Rok vydání: | 2009 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 97 This work synthesized polystyrene-b-polydimethylsiloxane block copolymers by living anionic polymerization of styrene and hexamethylcyclotrisiloxane, and investigated the surface properties of the block copolymers solutions. The number average molecular weights of PS-b-PDMS were 3×104~8×104 g/mole determined by gel permeation chromatography (GPC) and their polydispersities were between 1.033 and 2.276. The DMA and H-NMR analysis of PS-b-PDMS block copolymers confirmed that the products consisted of two different blocks. In solution surface properties aspect, because the polydimethylsiloxane itself has a lower surface energy, therefore increasing the content of the polydimethylsiloxane comes after the decrease of the surface tension value. The critical micelle concentration (cmc) were determined by surface tension measurement and the size of micelle was measured by a particle size analyzer. The conclusion is that enhancing the copolymer concentration raises the size of suspending component but after surpassing a critical micelle concentration the size increases rapidly because the micelle agglomeration is serious, it is unable to obtain correct micelle hydraulic radius (Rh). The micelle size at CMC was estimated as 10nm, that result is close to that from dynamic light scattering measurment (Rh). |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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