Dr. Thomas Junkers (2003 - 2006)

e-mail homepage (http://www.imo.uhasselt.be/default.htm) Hasselt University Campuslaan 1 -Gebouw D 3590 Diepenbeek Belgium

• free radical polymerization of (meth-)acrylates and itaconates / other similar monomers
• controlled (living) radical polymerization: RAFT (reversible addition-fragmentation transfer polymerization

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Bei der SP-PLP-ESR Technik wird die Abnahme der Intensität des ESR-Spektrums von propagierenden Radikalen in einer Monomer/Initiator-Lösung nach Einstrahlen eines Laserpulses (Excimer, 351 nm) zeitaufgelöst gemessen. Aus den so gewonnenen Informationen über die Abnahme der Radikalkonzentration können durch Anpassen verschiedener kinetischer Modelle Terminierungskoeffizienten als Funktion von Umsatz, Temperatur und der Kettenlänge sehr genau bestimmt werden.

PCGG activities

Cooperation(s):

• Hachenberg - Samwer group (SEC of PMMA)
• Hachenberg - Samwer group (RAFT Polymers)
• Scharf, Süske - Krebs group (SEC of PLD-PMMA under different deposition parameters)
• Vana - Buback group (Untersuchung von Polymeren mit scharfer Kettenlängenverteilung (RAFT))
• Steisel - Buback group (Charakterisierung der Kettenlängenverteilung mittels SEC (geplant) )

• Analytical laser induced liquid beam desorption mass spectrometry of biomolecules and their aggregates (planned)
  

• ♦ M. Buback, T. Junkers, M. Müller, Free-radical propagation and termination kinetics of the butyl acrylate dimer studied by pulsed laser polymerization techniques , Polymer 2009, 50, 3111-3118.
• ♦ M. Buback, P. Hesse, T. Junkers, T. Sergeeva, T. Theist, PLP Labeling in ESR spectroscopic analysis of secondary and tertiary acrylate propagating radicals, Macromolecules 2008, 41, 288-291.
• ♦ M. Buback, P. Hesse, T. Junkers, T. Theis, P. Vana, Chain-Length Dependent Termination in Acrylate Radical Polymerization Studied via Pulsed-Laser-Initiated RAFT Polymerization, Aust. J. Chem. 2007, 60, 779-787.
• ♦ M. Buback, T. Junkers, P. Vana, Pulsed-Laser Initiated RAFT Polymerization, Controlled/Living Radical Polymerization: From Synthesis to Materials (ACS Symposium Series) 2006, 944, 455-472.
• ♦ E. Süske, T. Scharf, T. Junkers, M. Buback, H.-U. Krebs, Mechanism of poly(methyl methacrylate) film formation by pulsed laser deposition, J. Appl. Phys. 2006, 100, 014906.
• ♦ M. Buback, P. Hesse, T. Junkers, P. Vana, Determination of Addition and Fragmentation Rate Coefficients in RAFT Polymerization via Time-Resolved ESR Spectroscopy after Laser Pulse Initiation, Macromol. Rapid Commun. 2006, 27, 182-187.
• ♦ M. Buback, T. Junkers, Termination kinetics of tert-butyl methacrylate and of n-butyl methacrylate free-radical bulk homopolymerizations, Macromolecular Chemistry and Physics 2006, 207(18), 1640-1650.
• ♦ S. Beuermann, M. Buback, P. Hesse, T. Junkers, I. Lacík, Free-radical polymerization kinetics of 2-acrylamido-2-methylpropanesulfonic acid in aqueous solution, Macromolecules 2006, 39, 509-516.
• ♦ E. Süske, T. Scharf, H.-U. Krebs, E. Panchenko, T. Junkers, M. Egorov, M.Buback, H. Kijewski, Tuning of cross-linking and mechanical properties of laser deposited poly(methyl methacrylate) films, J. Appl. Phys. 2005, 97, 63501 (1-4).
• ♦ M. Buback, M. Egorov, T. Junkers, E. Panchenko, Termination kinetics of di-n-butyl itaconate free-radical polymerization studied via the SP-PLR-ESR technique, Macromol. Chem. Phys. 2005, 3, 333.
• ♦ M. Buback, T. Junkers, P. Vana, Laser Single Pulse Initiated RAFT Polymerization for Assessing Chain-Length Dependent Radical Termination Kinetics, Macromol. Rapid Commun. 2005, 26, 796-802.
• ♦ T. Junkers, A. Theis, M. Buback, T.P. Davis, M. H. Stenzel, P. Vana, C. Barner-Kowollik, Chain-Length Dependent Termination in Butyl Acrylate Free-Radical Polymerization Studied via Stationary and Pulsed Laser Initiated RAFT Polymerization, Macromolecules 2005, 38, 9497-9508.
• ♦ R. X. E. Willemse, A. van Herk, E. Panchenko, T. Junkers, M. Buback, PLP-ESR monitoring of mid-chain radicals in n-butyl acrylate polymerization, Macromolecules 2005, 38, 5098-5103.
• ♦ M. Buback, M. Egorov, T. Junkers, E. Panchenko, Free-Radical Termination Kinetics Studied Using a Novel SP-PLP-ESR Technique, Macromol. Rapid Commun. 2004, 25, 1004-1009.

• Poster: Mar 21 2006 Novel methods for probing the termination kinetics in radical polymerization (Review Colloquium)
• Organization: Mar 08 2006 Host student of B. Charleux (Seventh Workshop 2006
  Spectroscopy and Dynamics of Molecular Coils and Aggregates (Göttingen - Paris))
• Poster: Mar 08 2006 Novel methods for probing the termination kinetics in radical polymerization (Seventh Workshop 2006
  Spectroscopy and Dynamics of Molecular Coils and Aggregates (Göttingen - Paris))
• Organization: Sept 05 2005 Organizing Comitee and Session Chair (Sixth Workshop 2005)
• Talk: Sept 05 2005 Deducing chain-lenght dependent termination rate coefficients by employing RAFT polymerization (Sixth Workshop 2005)
• Poster: April 05 2005 Chain-length dependence of termination rate coefficients studied via laser single pulse -RAFT-controlled polymerization (Fifth Workshop = 91st Bunsen Colloquium 2005)
• Poster: April 05 2005 Accurate termination rate coefficients from time-resolved Single Pulse - Pulsed Laser Polymerization - ESR experiments (Fifth Workshop = 91st Bunsen Colloquium 2005)
• Poster: April 01 2005 Mechanism of pulsed laser deposited PMMA (Frühjahrstagung der Deutschen Physikalischen Gesellschaft, Berlin 2005 )
• Poster: Sept 20 2004 Occurrence of tertiary radicals in acrylate polymerization (Fourth Workshop 2004)
• Poster: Sept 20 2004 Single Pulse-Pulsed Laser Polymerization-ESR (Fourth Workshop 2004)
• Talk: Mar 19 2004 Chain length dependent termination kinetics in free radical polymerization: single pulse – pulsed laser polymerization (Third Workshop 2004)
• Poster: Jan 01 2004 Pulsed Laser Polymerization in Conjunction with ESR Detection: A Novel Tool for Investigations into Free-Radical Termination Kinetics (Proceedings of the 40th IUPAC International Symposium on Macromolecules "MACRO 2004", Paris 2004, P1)
• Poster: Jan 01 2003 Single Pulse - Pulsed Laser Polymerization with time resolved ESR detection: A new tool to determine free-radical termination kinetics (8th EGS workshop, Clausthal 2003)