The present work is dealing with
the first synthesis and characterisation of amphiphilic diblock copolymers bearing b-dicarbonyl
(acetoacetoxy) chelating residues. Polymers were obtained by Group Transfer Polymerisation
(GTP)/acetoacetylation and controlled radical polymerisation techniques (RAFT).<br><br>Different
micellar morphologies of poly(n-butyl methacrylate)-block-poly[2-(acetoacetoxy)ethyl methacrylate]
(pBuMA-b-pAEMA) were observed in cyclohexane as a selective solvent. Depending on the block
length ratio, either spherical, elliptical, or cylindrical micelles were formed. The density of
the polymer chains at the core/corona interface is considerably higher as compared to any other strongly
segregating system reported in the literature. It is demonstrated that there are H-bond interactions
existing between acetoacetoxy groups, which increase the incompatibility between block segments. In
addition, such interactions lead to the formation of secondary structures (such as b-sheets or globular
structures) and larger superstructures in the micrometer length scale.<br><br>Block copolymers were also
used to solubilise metal ion salts of different geometries and oxidation states in organic media, in which
are otherwise insoluble. Sterically stabilised colloidal hybrid materials are formed, i.e.
monodisperse micelles having the metal ion salt incorporated in their core upon complexation with the
ligating pAEMA block, whereas pBuMA forms the solvating corona responsible for stabilisation in solution.
Systematic studies show that the aggregation behaviour is dependent on different factors, such as
the tautomeric form of the beta-dicarbonyl ligand (keto/enol) as well as the nature and amount of added
metal ion salt.
| Identifer | oai:union.ndltd.org:Potsdam/oai:kobv.de-opus-ubp:84 |
| Date | January 2003 |
| Creators | Krasia, Theodora |
| Publisher | Universität Potsdam, Mathematisch-Naturwissenschaftliche Fakultät. Institut für Chemie |
| Source Sets | Potsdam University |
| Language | English |
| Detected Language | English |
| Type | Text.Thesis.Doctoral |
| Format | application/pdf |
| Rights | http://opus.kobv.de/ubp/doku/urheberrecht.php |
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