|132. Storsberg, J.; Ritter, H.; Hartenstein, M.; Müller, A.H.E.: Cyclodextrins in polymer synthesis: Polymerization of methyl methacrylate under atom transfer conditions (ATRP) in aqueous solution, Macromolecular Rapid Communications 21, 1342 (2000) -- DOI: 10.1002/1521-3927(20001201)21:18<1342::AID-MARC1342>3.0.CO;2-Z|
Host guest complexes of methyl methacrylate (MMA) and randomly methylated b-cyclodextrin (m-b-CD, 1 a) were polymerized in aqueous medium using atom-transfer radical polymerization. Ethyl 2-bromoisobutyrate (EBIB) was used as an initiator, copper(I) bromide as the catalyst, and bipyridine (bipy) or 4,4'-di-(5-nonyl)-2,2'-bipyridine (dNbipy) as ligands. The unthreading of m-b-CD during the polymerization led to water-insoluble poly(methyl methacrylate) (PMMA). It was found that using dNbipy resulted in higher monomer conversion than using bipy as the ligand under similar conditions. Furthermore, it is shown that the polymerization of MMA under these conditions has a living character. The polymers obtained have a much lower polydispersity than those obtained from conventional free-radical polymerization. Also, the block copolymerization of PMMA bearing a bromoester end group with CD-complexed styrene (2 a) was carried out under ATRP conditions in aqueous medium.