POLY 172 |
| Abstract: We report the synthesis of hydrophilic poly(N,N-dimethylacrylamide) (PDMA) brushes from latex surfaces anchored with chain transfer agent (CTA by aqueous reversible addition-fragmentation chain transfer (RAFT) polymerization. Dithiobenzoate (CTA) was covalently attached to the surface of polystyrene latex by a neucleophilic substitution reaction of a-bromine of 2-bromo propionate (ATRP initiator) anchored to the latex surface with sodium dithiobenzoate. The surface concentration of CTA was measured by UV-vis spectroscopy. N,N-Dimethylacrylamide was polymerized under RAFT conditions in the presence of water soluble 2,2'-azobis(2-amidinopropane)dihydrochloride a cationic azo initiator at different conditions. Analysis of grafted polymers after cleaving it from the surface shows that high molecular weight PDMA was grafted onto the surface. Control of the molecular weight was achieved by the addition of soluble free CTA in the polymerization medium. Our results indicate that, surface interactions of charged water soluble initiators, monomer concentration and the presence of water soluble free CTA influence the surface initiation and subsequent polymer brush growth. Low D/Rg values (D = distance between grafted sites, Rg - radius of gyration) of the grafted polymer chains show that they are in the brush regime and is supported by the large hydrodynamic thickness of the PDMA layer. |
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General Papers: Synthesis and Characterization
6:00 PM-8:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster
Sci-Mix
Division of Polymer Chemistry |