ERA-CHEMISTRY_Nanokompartimentierte polymere ionische Flüssigkeiten als neue Materialplattform für das Maßschneidern von responsiven makromolekularen Systemen
Zusammenfassung der Projektergebnisse
Tailoring of novel functional and responsive macromolecular systems has been achieved by creation of nano-compartmentalized polymeric ionic liquid (NCPIL) micelles, which combine polyisobutylene (PIB), poly(2-alkyl-2-oxazoline) (POX), and ionic liquid (IL) groups. Aiming at intermediates for NCPIL creation, robust procedures have been developed that allow for the synthesis of various perfectly end-functionalized PIBs. Benzotrifluoride (BTF), which is also compatible with non-polar PIB, was identified as suited solvent for cationic ring-opening polymerization (CROP) of 2-ethyl-2-oxazoline (EtOx) and enables the production of well-defined poly(2-ethyl-2-oxazoline) (PEtOx) chains. Termination with alkylimidazoles yielded novel IL-terminated PEtOx species and ionic macromonomers which can be readily polymerized, thus opening way to thermoresponsive PILs with graft architectures. By using 1-iodooctadecane as initiator for EtOx polymerization and/or 1-dodecylamine as terminating agent, hydrophobically modified PEtOx have been prepared, whose critical micelle concentration and cloud points were found to strongly depend on substitution pattern and molecular weight. Concerning nanostructured PIL materials, IL-terminated PIBs were synthesized by simple methylation reactions. Rheological investigations and SAXS analysis reveal temperature-dependent nanostructural selfassembly and expand the knowledge about ionic PIBs. Moreover, new nanoconfined PILs were prepared from poly(N-vinylimidazole)-l-poly(tetrahydrofuran) conetworks. Owing to unique swelling behavior, these PILs can be used for applications such as nanocatalysis or ion conducting materials. Several attempts were made so synthesize NCPILs as unimolecular micelles by coupling PIB derivatives with hyperbranched poly(3-ethyl-3-hydroxymethyloxetane) (PEHO) or poly(ethyleneimine) cores but failed due to miscibility problems and side reactions. As a proof of principle, coupling of imidazolefunctionalized PEHO and PIB-tosylate worked to some extent, but coupling efficiency was low and the NCPILs could not be isolated. Generation of NCPILs with PIB-b-POX block copolymer shells failed as well, since the PIB-tosylates turned out to be inefficient initiators for EtOx polymerization, contrary than expected. However, another strategy for NCPIL design was successful. By termination of the CROP of EtOx in BTF or BTF:DMF mixture with imidazole-terminated PIB, highly defined amphiphilic PIB-b- PEtOx diblock copolymers bearing an imidazolium cation as single IL moiety, which covalently couples both blocks, were synthesized. Hydrophilic/hydrophobic balance and thus properties of these PIB-IL-PEtOx copolymers are easily adjusted by variation of the block length ratio. As a function of the PEtOx block length, self-assembly of the copolymers results either in water-soluble spherical and elongated PIL micelles or in hydrogel-forming worm-like nanostructures. The water-soluble PIB-IL-PEtOx micelles display thermoresponsive LCST behavior with composition-dependent cloud points. The hydrogels exhibit thermoresponsive features as well. Finally, the unique PIB-IL-PEtOx diblock copolymers were found to enable thermally switchable solubilization, dispersion, and shuttling of molecules and nanomaterials and, thus, offer new opportunities in the creation of advanced functional NCPIL systems.
Projektbezogene Publikationen (Auswahl)
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Synthesis of novel type of functional macromolecules by quasi living polymerizations and subsequent modifications. In: International Conference on Polymer Science & Engineering, New Orleans, USA, August 22-24, 2016. Journal of Material Sciences & Engineering 5:(6) p. 74 (2016)
Balázs Pásztói, György Kasza, Ákos Szabó, Béla Iván
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Synthesis of novel type of functional macromolecules by quasiliving polymerization and subsequent modifications. In: World congress on living polymerizations and polymers (LPP16), Budapest, Hungary, May 29-June 3, 2016. Book of Abstracts 145 p.
Balázs Pásztói, György Kasza, Ákos Szabó, Béla Iván
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Endfunctional Polyisobutylenes as Building Blocks of Multicomponent Macromolecular Assemblies. In: Macromolecular Colloquium, Freiburg, Germany, February 15-17, 2017. Macromolecular Chemistry and Physics 218:(2) p. F19. (2017)
Balázs Pásztói, Tobias Trötschler, Ákos Szabó, Benjamin Kerscher, Béla Iván, Rolf Mülhaupt
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Synthesis, characterization and thermoresponsive behavior of hydrophobically modified poly(2-ethyl-2-oxazoline)s. In: 17th Polymers and Organic Chemistry Conference, Palavas Les Flots, France, June 3-7, 2018. Book of Abstracts P38
Balázs Pásztói, Tobias M. Trötschler, Ákos Szabó, Benjamin Kerscher, Heikki Tenhu, Rolf Mülhaupt, Béla Iván
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Synthesis, characterization and thermoresponsive behaviour of hydrophobically modified poly(2-ethyl-2-oxazoline)s In: 8th International Conference on Polymer Science and Engineering, Las Vegas, Nevada, USA, October 15-16, 2018. Journal of Advanced Chemical Engineering, Volume 8, October 2018, ISSN: 2090-4568. Page 32
Balázs Pásztói, Tobias M. Trötschler, Ákos Szabó, Benjamin Kerscher, Heikki Tenhu, Rolf Mülhaupt, Béla Iván
