Novel Amphiphilic Multi-Arm, Star-Like Block Copolymers as Unimolecular Micelles
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SCOPUS
- Title
- Novel Amphiphilic Multi-Arm, Star-Like Block Copolymers as Unimolecular Micelles
- Authors
- Pang, XC; Zhao, L; Akinc, M; Kim, JK; Lin, ZQ
- Date Issued
- 2011-05-24
- Publisher
- AMER CHEMICAL SOC
- Abstract
- A series of novel amphiphilic multiarm, star-like block copolymers, poly(acrylic acid)-b-polystyrene (PAA-b-PS) based on beta-cyclodextrin (beta-CD) with well-defined molecular architectures, molecular weight, and ratio of two dissimilar blocks were prepared by sequential atom transfer radical polymerization (ATRP). beta-CD with 21 hydroxyl groups was esterified by the reaction of its hydroxyl end groups with 2-bromoisobutyryl bromide, producing star-like heptakis[2,3,6-tri-O-(2-bromo-2-methylpropionyl]-beta-cyclodextrin) (denoted 21-Br-beta-CD). Subsequently, 21-Br-beta-CD was utilized to initiate sequential ATRP of tert-butyl acrylate (tBA) and styrene (St). A series of 21-arm, star-like diblock copolymers, poly(tert-butyl acrylate)-b-polystyrene (PtBA-b-PS) were thus obtained. Finally, the ester groups of tBA in star-like PrBA-b-PS were selectively hydrolyzed by trifluoroacetic acid (TFA), thereby yielding amphiphilic 21-arm, star-like diblock copolymer PAA-b-PS with narrow molecular weight distribution (polydispersity index, PDI < 1.2). The intermediate and final products were systematically characterized and confirmed by GPC, (1)H NMR and FT-IR. The unimolecular micelles (i.e., composed of single copolymer molecule) formed from amphiphilic star-like PAA-b-PS were analyzed by dynamic light scattering, TEM, and AFM.
- Keywords
- TRANSFER RADICAL POLYMERIZATION; FRAGMENTATION CHAIN-TRANSFER; HYPERBRANCHED POLYGLYCEROL CORE; POLYMERS; ACID); POLYSTYRENE; DENDRIMERS; BRUSHES; FLUORESCENCE; ADSORPTION
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/17400
- DOI
- 10.1021/MA200594J
- ISSN
- 0024-9297
- Article Type
- Article
- Citation
- MACROMOLECULES, vol. 44, no. 10, page. 3746 - 3752, 2011-05-24
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- There are no files associated with this item.
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