TY - JOUR A1 - Schmid, C. A1 - Weidner, Steffen A1 - Falkenhagen, Jana A1 - Barner-Kowollik, C. T1 - In-depth LCCC-(GELC)-SEC characterization of ABA block copolymers generated by a mechanistic switch from RAFT to ROP N2 - A recently introduced procedure involving a mechanistic switch from reversible addition–fragmentation chain transfer (RAFT) polymerization to ring-opening polymerization (ROP) to form diblock copolymers is applied to synthesize ABA (star) block copolymers. The synthetic steps include the polymerization of styrene with R-group designed RAFT agents, the transformation of the thiocarbonyl thio end groups into OH functionalities, and their subsequent chain extension by ROP. The obtained linear ABA poly(ε-caprolactone)-block-poly(styrene)-block-poly(ε-caprolactone) (pCL-b-pS-b-pCL) (12 500 g mol–1 ≤ Mn ≤ 33 000 g mol–1) and the star-shaped poly(styrene)-block-poly(ε-caprolactone) (Mn = 36 000 g mol–1) copolymers were analyzed by size exclusion chromatography (SEC), nuclear magnetic resonance (NMR), infrared (IR) spectroscopy, and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The focus of the current study is on the detailed characterization of the ABA (star) block polymers via multidimensional chromatographic techniques specifically high performance liquid chromatography coupled to size exclusion chromatography (HPLC-SEC). In particular, we demonstrate the first time separation of poly(ε-caprolactone) (pCL) homopolymer and additionally poly(styrene) (pS) from the ABA poly(ε-caprolactone)-b-poly(styrene)-b-poly(ε-caprolactone) and star-shaped poly(styrene)-b-poly(ε-caprolactone) block copolymer utilizing critical conditions (CC) for pCL with concomitant gradient elution liquid chromatography (GELC). KW - Two-dimensional-liquid chromatography (2D-LC) KW - Liquid chromatography under critical conditions (LCCC) KW - Gradient elution liquid chromatography (GELC) KW - Soft ionization mass spectrometry (ESI, MALDI) KW - Reversible addition fragmentation chain transfer (RAFT) KW - Ring opening polymerization (ROP) PY - 2012 DO - https://doi.org/10.1021/ma2022452 SN - 0024-9297 SN - 1520-5835 VL - 45 IS - 1 SP - 87 EP - 99 PB - American Chemical Society CY - Washington, DC AN - OPUS4-25464 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Friedrich, Jörg Florian A1 - Kühn, Gerhard A1 - Mix, Renate A1 - Retzko, Iris A1 - Gerstung, Vanessa A1 - Weidner, Steffen A1 - Schulze, Rolf-Dieter A1 - Unger, Wolfgang ED - Mittal, K. L. T1 - Plasma polymer adhesion promoters for metal-polymer systems T2 - 2nd International Symposium on Polyimides and Other High Temperature Polymers: Synthesis, Characterization and Applications CY - Newark, NJ, USA DA - 2001-12-03 KW - r.f. pulsed plasma KW - Plasma polymers with functional groups KW - Copolymers KW - Adhesion promoting interlayers KW - Metal-polymer systems PY - 2003 SN - 90-6764-378-5 VL - 2 SP - 359 EP - 388 PB - VSP CY - Utrecht AN - OPUS4-6967 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Friedrich, Jörg Florian A1 - Ghode, Archana A1 - Kühn, Gerhard A1 - Weidner, Steffen A1 - Geng, Shiming A1 - Retzko, Iris A1 - Unger, Wolfgang A1 - Lippitz, Andreas ED - Schindel-Bidinelli, E. T1 - Polymeroberflächenfunktionalisierungen im gepulsten Plasma mit nachfolgender chemischer Behandlung T2 - 14. Internationales Symposium Swissbonding ; 14. Internationaler Kongreß Swiss Bonding ; 14th Swiss Bonding 00 CY - Rapperswil, Schweiz DA - 2000-05-16 PY - 2000 SP - 31 EP - 44 PB - SWIBOTECH GmbH CY - Bülach AN - OPUS4-6980 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Friedrich, Jörg Florian A1 - Unger, Wolfgang A1 - Lippitz, Andreas A1 - Weidner, Steffen A1 - Geng, Sh. A1 - Wigant, L. A1 - Wöll, Ch. A1 - Erdmann, J. A1 - Gorsler, H.-V. T1 - Characterization of plasma-modified organic surfaces by electron spectroscopy, SEIRA, and MALDI-TOF-MS T2 - 6th European Conference on Applications of Surface and Interface Analysis CY - Montreux, Switzerland DA - 1995-10-09 PY - 1995 SP - TC 11 PB - Wiley CY - Chichester AN - OPUS4-7001 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidner, Steffen A1 - Kühn, Gerhard A1 - Friedrich, Jörg Florian T1 - Infrared-Matrix-assisted Laser Desorption/Ionization and Infrared-Laser Desorption/Ionization Investigations of Synthetic Polymers PY - 1998 SN - 0951-4198 SN - 1097-0231 VL - 12 SP - 1373 EP - 1381 PB - Wiley CY - Chichester AN - OPUS4-6988 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cherbib, S. A1 - Jlalia, I. A1 - Chabbah, T. A1 - Chatti, S. A1 - Marestin, C. A1 - Mercier, R. A1 - Weidner, Steffen A1 - Casabianca, H. A1 - Jaffrezic-Renault, N. A1 - Abderrazak, H. T1 - Design of New Partially Bio-Based Polyguanamines for the Reversible Adsorption of Phenolic Molecules from Olive Mill Wastes N2 - Olive mill wastewater produces a variety of potent antioxidants, including hydroxytyrosol, oleuropein, and tyrosol, that have been widely used in agriculture, pharmacy, and cosmetics. This study aims to design new poly(guanamine)s phases by polycondensation of modified triazine monomers with both petro-based and biosourced diamines, to act as stationary phases for the uptake of these phenolic molecules. Obtained polymers were characterized by NMR spectroscopy, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The adsorption results showed that the newly synthesized polymers can effectively uptake the less polar phenolic compounds, ferulic acid, and caffeic acid. The isosorbide-based polymer (P6) presented the highest sorption efficiency, due to the hydrophilic properties of isosorbide associated with the proton affinity of the triazine groups. All the phenolic compounds were successfully desorbed from the P6 polymer using a minimal amount of a methanol/acetonitrile mixture. P6 polymer could be used for four successive adsorption processes without loss of efficiency. KW - Olive mill wastewater KW - Triazine KW - Isosorbide KW - Adsorption KW - Phenolic compounds PY - 2024 DO - https://doi.org/10.1007/s42250-024-01081-3 SN - 2522-5758 SP - 1 EP - 11 PB - Springer Science and Business Media LLC AN - OPUS4-61348 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - Cyclic polylactides via ring-expansion polymerization N2 - We will report on a new kind of ring-expansion polymerization (REP) of cyclic esters based of three classes of catalysts. In contrast to REP described previously these new polymerizations are characterized by a self-extrusion of the catalysts resulting in cyclic homopolyesters as the only reaction product. These REP of L-lactide were performed in bulk at temperatures between 100 and 180°C without racemization. A simplified scheme of a REP catalyzed by BuCa or SnBi is presented below. With meso-lactide temperatures down to 60°C were realized. Depending on catalyst, time and temperature with equal quantities of even and odd-numbered cycles a strong predominance of either even or odd-numbered cycles was found. T2 - 255th ACS National Meeting CY - New Orleans, LA, USA DA - 18.03.2018 KW - MALDI-TOF MS KW - Poly(lactide) KW - Polymerisation KW - Catalysts PY - 2018 AN - OPUS4-44833 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - MALDI TOF MS zur Aufklärung von Kristallisationsprozessen in Polyestern N2 - MALDI TOF Massenspektrometrie wurde verwendet, um Kristallisationsprozesse in Polyestern (Polylactide, Polyglycolide) zu untersuchen. Dabei konnte gezeigt werden, dass Zyklen und Linearen simultan, aber in unterschiedlichen Kristalliten, kristallisieren. Die dabei ablaufenden Umesterungen (Transesterifizierungen) konnten mit der MALDI TOF Massenspektrometrie nachgewiesen werden. Damit wurde ein völlig neues Anwendungsgebiet dieser MS Methode demonstriert. T2 - 28. Kolloquium Massenspektrometrie von Polymeren CY - Berlin, Germany DA - 14.05.2024 KW - MALDI TOF MS KW - Bioabbaubare Polymere KW - Crystallinity PY - 2024 AN - OPUS4-60029 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - MassChrom2D - a software that combines chromatographic separation and mass spectrometric identification to analyze the composition of copolymers T2 - 60th ASMS Conference on Mass Spectrometry and Allied Topics CY - Vancouver, Canada DA - 2012-05-20 PY - 2012 AN - OPUS4-25954 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - MALDI - Untersuchung zur Oberflächenmodifizierung von Polymeren nach Plasmabehandlung T2 - 4. MALDI-Anwendertreffen (Shimadzu) CY - Duisburg, Germany DA - 1997-11-26 PY - 1997 AN - OPUS4-11280 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -