Synthesis and Characterization of C60-Anchored Multiarmed Polymers with Well-Defined Structures
Journal
Macromolecules
Journal Volume
39
Journal Issue
17
Pages
5657-5668
Date Issued
2006
Author(s)
Abstract
A multistep procedure for preparing novel C60-anchored multiarmed polymers with well-defined structures was developed. First, di-, tetra- and octabromo-functionalized molecules with a malonate ester core were synthesized and used as functional initiators for growing two-, four-, and eight-armed poly(tert-butyl acrylate) (PtBA) with well-controlled molecular weight, by atom transfer radical polymerization. Then, C60-anchored polymers were synthesized by the effective Bingel reaction between C60 and the malonate ester core of the multiarmed polymers. The NMR analyses of the products demonstrated that C60 had been covalently bonded to the polymers and UV−vis studies of these polymers revealed strong characteristics of “closed” 6−6-ring-bridged methanofullerene derivatives. As indicated by GPC chromatograms, the molecular weights of the polymers were comparable before and after they are attached to C60 molecules, suggesting that these polymers were monosubstituted C60 derivatives. Furthermore, the C60 contents in these polymers were determined from their light absorbance at 326 nm based on Beer's law and were found to be very close to the theoretical value based on the assumption that C60-derived polymer was a monoadduct. Additionally, highly water-soluble C60-anchored multiarmed poly(acrylic acid) were obtained in quantitative yield by the hydrolysis of the C60-anchored multiarmed PtBA in the presence of trifluoroacetic acid at room temperature.
Publisher
American Chemical Society
Type
journal article