Entwicklung und Anwendung neuer Katalysatoren für die Atom Transfer Radikal Polymerisation
Zusammenfassung der Projektergebnisse
Transition metal catalyzed atom transfer radical polymerization (ATRP) is one of the most extensively studied reversible deactivation radical polymerization (RDRP) methods nowadays. It presents a versatile technique for exerting precise control over polymer molecular weights, molecular weight distributions, and complex architectures. Polymers prepared by ATRP are highly chain end-functionalized and therefore can participate in various post-polymerization modifications. ATRP is based on the reversible reaction of a low oxidation-state metal complex Mt(z)L (e.g., Mt = Cu, Ru, Fe, z = oxidation state, L = Ligand) with an alkyl halide (RX) yielding radicals and the corresponding metal complex, X-Mt(z+1)L. The development of new ATRP catalysts and novel polymerization systems based on rational ligand design was the aim during the stay at CMU. Active copper catalysts were developed, which enable to work with only ppm amount of metal complex, and achieve excellent control over the resulting polymers. The novel Cu/tris((4-methoxy-3,5-dimethylpyridin-2-yl)methyl)amine (TPMA*) system is currently the most reducing and the most active catalyst for acrylates employing atom transfer radical polymerizations (ATRP). A variety of derivates of the tris(2-pyridylmethyl)amine) scaffold could be synthesized, characterized, studied and successfully applied in polymerizations of methyl methacrylate and acrylates. A concept for using these active catalysts was developed and their participation in organometallic-mediated radical polymerization (OMRP) under certain conditions investigated. In addition, various iron complexes were studied and applied in ATRP reactions, but a state-of-the-art system remains to be a challenge.
Projektbezogene Publikationen (Auswahl)
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“Formation and Possible Reactions of an Organometallic Intermediate with Active Copper(I) Catalysts in an ATRP”, Organometallics 2012, 7994-7999
K. Schröder, D. Konkolewicz, R. Poli, K. Matyjaszewski
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“Substituted Tris(2-pyridylmethyl)amine Ligands for Highly Active ATRP Catalysts”, ACS Macro Lett. 2012, 1, 1037-1040
K. Schröder, R. T. Mathers, J. Buback, D. Konkolewicz, A. J. D. Magenau, K. Matyjaszewski
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“Visible Light and Sunlight Photoinduced ATRP with ppm of Cu Catalyst”, ACS Macro Lett. 2012, 1219-1223
D. Konkolewicz, K. Schröder, J. Buback, S. Bernhard, K. Matyjaszewski
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“Reversible-Deactivation Radical Polymerization of Methyl Methacrylate and Styrene Mediated by Alkyl Dithiocarbamates and Copper Acetylacetonates”, Macromolecules 2013, 5512-5519
Y. Zhang, K. Schröder, Y. Kwak, P. Krys, A. N. Morin, T. Pintauer, R. Poli, K. Matyjaszewski
