TY - CONF A1 - Sonnenschein, Helmut A1 - Kreher, Th. A1 - Krüger, Ralph-Peter A1 - Ahlers, B. T1 - Synthesis of brigded indolizines-starting materials for molecular tweezers T2 - XVI th European Colloquium on Heterocyclic Chemistry CY - Bled, Slovenia DA - 1994-09-25 PY - 1994 CY - Bled, Slovenia AN - OPUS4-2198 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Paulus, G. A1 - Resch, M. A1 - Schulz, Günter ED - Darms, R. ED - Suter, U. T1 - Polymer Characterization by MALDI-TOF-MS and Combination with HPLC T2 - 5th European Polymer Federation Symposium on Polymeric Materials (EPF) CY - Basel, Switzerland DA - 1994-10-09 PY - 1994 SN - 3-85739-297-5 SN - 0258-0322 VL - 5 PB - Hüthig & Wepf CY - Zug AN - OPUS4-2200 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Maier, Bärbel A1 - Much, Helmut A1 - Schulz, Günter T1 - Orthogonal two-dimensional chromatography of poly(ethylene oxid) adducts T2 - HPLC '96 CY - San Francisco, CA, USA DA - 1996-06-16 PY - 1996 CY - San Francisco AN - OPUS4-2221 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter A1 - Frey, H. T1 - Characterization of unusual Silsesquioxane-Based Polymer Architectures Based on the Coupling of Liquid Chromatography and MALDI-TOF-MS T2 - 11th International Symposium on Organosilicon Chemistry CY - Montpellier, France DA - 1996-09-01 PY - 1996 CY - Montpellier AN - OPUS4-2222 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Much, Helmut A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Schulz, Günter ED - Berger, T. T1 - New methods for characterization of polymer heterogeneity by combination of HPLC with MALDI-TOF-MS T2 - 21st International Symposium on Chromatography CY - Stuttgart, Germany DA - 1996-09-15 PY - 1996 SN - 0009-5893 IS - 45 PB - Vieweg CY - Wiesbaden AN - OPUS4-2223 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, A. A1 - Krüger, Ralph-Peter T1 - Quantitative analysis of molecular weight distribution obtained by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry T2 - DECHEMA-Diskussionstagung "Neue Methoden der Polymeranalytik" CY - Mainz, Germany DA - 1996-10-07 PY - 1996 CY - Mainz AN - OPUS4-2224 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Pickard, M. A1 - Schulz, Günter A1 - Wachsen, O. T1 - Characterization of thermal and hydrolytic degradation of polylactides by Liquid Chromatography and MALDI-TOF mass spectrometry T2 - International Symposium on "Biodegradable Materials" and Hamburger Makromolekulares Symposium CY - Hamburg, Germany DA - 1996-10-07 PY - 1996 CY - Hamburg AN - OPUS4-2225 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter ED - Fell, A. T1 - Two-dimensional chromatography, their optimization and coupling with different detection techniques for investigation of polymer heterogeneity T2 - 21st International Symposium on High Performance Liquid Phase Separations and Related Techniques (HPLC) CY - Birmingham, England, UK DA - 1997-06-22 PY - 1997 SN - 0021-9673 PB - Elsevier CY - Amsterdam AN - OPUS4-2232 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter T1 - Coupling of different modes of liquid chromatography of polymers with spectroscopic methods and MALDI-TOF-MS-key for determination of polymer heterogeneity T2 - 6th SPSJ International Polymer Conference (IPC 97) CY - Kusatsu, Japan DA - 1997-10-20 PY - 1997 VL - 6 AN - OPUS4-2233 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rikowski, E. A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter T1 - Synthesis of Polyhedral Hexa-, Octa-, Deca- and Dodeca Silsesquioxanes, Separation by NP-HPLC, SEC and LACCC, Characterization by MALDI-TOF-MS T2 - 4. Münchener Silikontage CY - München, Germany DA - 1998-04-07 PY - 1998 VL - 4 AN - OPUS4-2234 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Much, Helmut A1 - Schulz, Günter A1 - Rikowski, E. T1 - Characterization of silicon polymers (silsesquioxanes, dendrimers and copolymers) by means of different modes of Liquid Chromatography and MALDI-TOF-MS PY - 1998 PB - Messe München GmbH CY - München AN - OPUS4-2236 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Much, Helmut A1 - Schulz, Günter T1 - Characterization of silicon polymers by means of different liquid chromatographic modes and MALDI-TOF-MS T2 - DFG-Symposium zum Schwerpunktprogramm "Silicium-Chemie" CY - Werfenweng, Austria DA - 1998-06-11 PY - 1998 AN - OPUS4-2237 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter T1 - Investigations of Polymer Heterogeneity by Two-Dimensional HPLC, MALDI-TOF-MS and FTIR Coupling T2 - ISPAC 8, HPLC ´95 CY - Sanibel Island, FL, USA DA - 1995-05-20 PY - 1995 PB - Gordon and Breach CY - Sant Helier AN - OPUS4-2203 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Much, Helmut A1 - Krüger, Ralph-Peter A1 - Schulz, Günter T1 - Investigation of Macromer Heterogeneity by Two-Dimensional HPLC and MALDI-TOF-MS T2 - 19th International Symposium on Column Liquid Chromatography CY - Innsbruck, Austria DA - 1995-05-28 PY - 1995 CY - Innsbruck AN - OPUS4-2204 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maier, B. A1 - Trathnigg, B. A1 - Much, Helmut A1 - Krüger, Ralph-Peter A1 - Berek, D. T1 - Characterization of polyethers using different chromatographic techniques and MALDI-TOF-MS PY - 1995 CY - Innsbruck AN - OPUS4-2205 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter T1 - Investigation of Macromer Heterogeneity by 2D-HPLC and MALDI-TOF-MS T2 - Präsentationsveranstaltung des Instituts für Angewandte Chemie Berlin-Adlershof e.V. CY - Berlin, Germany DA - 1995-09-26 PY - 1995 CY - Berlin AN - OPUS4-2207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Ralph-Peter A1 - Kricheldorf, H.R. A1 - Böhme, S. T1 - Macrocycles 16. Macrocyclic Dibutyltin Dicarboxylates by Ring-Closing Polycondensation N2 - Various dibutyltin derivatives were polycondensed with aliphatic ,-dicarboxylic acids having chain lengths from 4 (succinic acid) to 22 carbon atoms. White crystalline products were obtained from all experiments, and the structure of the products was independent of the synthetic method. Viscosity measurements revealed low molecular weights (n 1 500 Da) in all cases. Vapor pressure osmometry (VPO) measurements and matrix-assisted laser desorption time-of-flight (MALDI-TOF) mass spectrometry proved that cyclic dimers and trimer were formed from dicarboxylic acids having 6 to 16 carbons, but mainly the monomeric cycle from docosane dioic acid. Heating to 250°C did not change the structure. Therefore, the results indicate that the macrocycles are the result of a thermodynamically controlled ring-closing polycondensation. This means that linear high-molecular weight poly(dibutyltin dicarboxylate)s cannot exist above room temperature. PY - 2002 DO - https://doi.org/10.1002/1521-3935(20020101)203:2<313::AID-MACP313>3.0.CO;2-V SN - 1022-1352 SN - 1521-3935 VL - 203 IS - 2 SP - 313 EP - 318 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-1796 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Schulz, Günter A1 - Weidner, Steffen T1 - Polymer Characterization by LC / MALDI-MS Coupling T2 - Vortragstagung "Funktionspolymere für Systemlösungen" CY - Darmstadt, Germany DA - 2002-03-18 PY - 2002 AN - OPUS4-1805 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Schulz, Günter T1 - Characterization of polylactides by coupling of chromatographic methods with MALDI-TOF-MS T2 - Polydays 2002 ; ISPAC 2002 CY - Berlin, Germany DA - 2002-09-30 PY - 2002 AN - OPUS4-1807 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grimm, B. A1 - Krüger, Ralph-Peter A1 - Schrader, S. A1 - Prescher, D. T1 - Molecular structure investigations on fluorine-containing polyazomethines by means of MALDI-TOF-MS technique T2 - Berliner Polymerentage 2000 CY - Berlin, Germany DA - 2000-10-09 PY - 2000 CY - Berlin AN - OPUS4-2253 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter T1 - Characterization and identification of new polymer structures by optimization and coupling of HPLC and MALDI-TOF-MS T2 - Dechema-Diskussionstagung "Neue Methoden der Polymeranalytik" CY - Mainz, Germany DA - 2001-04-02 PY - 2001 CY - Mainz AN - OPUS4-2255 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Schulz, Günter A1 - Weidner, Steffen T1 - Polymer characterization by LC / MALDI-MS coupling T2 - Bayreuther Polymer Symposium 2001 CY - Bayreuth, Germany DA - 2001-09-16 PY - 2001 CY - Bayreuth AN - OPUS4-2256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Rikowski, E. A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter T1 - Characterization of silicon-polymers by liquid chromatography and MALDI-TOF-MS T2 - 37th IUPAC Congress ; 27th GDCh General Meeting CY - Berlin, Germany DA - 1999-08-14 PY - 1999 SN - 3-924763-80-1 PB - Gesellschaft Deutscher Chemiker CY - Frankfurt am Main AN - OPUS4-2241 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Prescher, D. A1 - Grimm, B. A1 - Krüger, Ralph-Peter A1 - Schrader, S. T1 - To the formation of F-containing polyazomethines - investigation of the reaction products by MALDI TOF mass spectrometry T2 - 16th International Symposium Fluorine Chemistry CY - Durham, England, UK DA - 2000-07-16 PY - 2000 AN - OPUS4-2246 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter A1 - Just, Ulrich ED - Yeung, E. T1 - Characterization of silicon polymers by coupling of liquid chromatographic methods with MALDI-TOF-MS T2 - 24th International Symposium on High Performance Liquid Phase Separations and Related Techniques ; 24th HPLC 2000 CY - Seattle, WA, USA DA - 2000-06-24 PY - 2000 SN - 0021-9673 PB - Elsevier CY - Amsterdam AN - OPUS4-2247 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bünger, H. A1 - Pison, U. A1 - Krüger, Ralph-Peter ED - Yeung, E. T1 - Separation of hydrophobic pulmonary surfactant proteins using preparative HPLC with UV detection T2 - 24th International Symposium on High Performance Liquid Phase Separations and Related Techniques ; 24th HPLC 2000 CY - Seattle, WA, USA DA - 2000-06-24 PY - 2000 SN - 0021-9673 PB - Elsevier CY - Amsterdam AN - OPUS4-2249 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter A1 - Weidner, Steffen ED - Grellmann, W. T1 - Characterization and identification of new polymer structures by optimization and coupling of HPLC and MALDI-TOF-MS T2 - Polymerwerkstoffe 2000 CY - Halle (Saale), Germany DA - 2000-09-25 PY - 2000 SN - 3-86010-605-8 PB - Martin-Luther-Univ. CY - Halle AN - OPUS4-2250 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Much, Helmut A1 - Schulz, Günter A1 - Rikowski, E. T1 - Characterization of silicon polymers (silsesquioxanes, dendrimers and copolymers) by means of different modes of Liquid Chromatography and MALDI-TOF-MS T2 - Analytica Conference '98 CY - Munich, Germany DA - 1998-04-21 PY - 1998 AN - OPUS4-3414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Much, Helmut A1 - Schulz, Günter A1 - Rikowski, E. T1 - Characterization of silicon polymers (silsesquioxanes, dendrimers and copolymers) by means of different modes of Liquid Chromatography and MALDI-TOF-MS T2 - ISPAC-11 CY - Santa Margherita Ligure, Italy DA - 1998-05-25 PY - 1998 AN - OPUS4-3415 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter A1 - Frey, H. T1 - Characterization of unusual Silsesquioxane-Based Polymer Architectures Based on the Coupling of Liquid Chromatography and MALDI-TOF-MS T2 - XIth International Symposium on Organosilicon Chemistry CY - Montpellier, France DA - 1996-09-01 PY - 1996 AN - OPUS4-3416 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter A1 - Pickard, M. A1 - Wachsen, O. T1 - Characterization of thermal and hydrolytic degradation of polylactides by Liquid Chromatography and MALDI-TOF mass spectrometry T2 - International Symposium on "Biodegradable Materials" and Hamburger Makromolekulares Symposium 1996 CY - Hamburg, Germany DA - 1996-10-07 PY - 1996 AN - OPUS4-3417 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter A1 - Wachsen, O. A1 - Reichert, K.H. A1 - Pickard, M. T1 - Characterization of Polymer Heterogeneity During Degradation Processes by Liquid Chromatography and MALDI-TOF-MS T2 - 9th International Symposium on Polymer Analysis and Characterization CY - Oxford, England DA - 1996-07-01 PY - 1996 AN - OPUS4-3453 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Ralph-Peter A1 - Kricheldorf, H.R. A1 - Böhme, S. T1 - Macrocyclic Dibutyltin Dicarboxylates via Thermodynamically Controlled Polycondensations KW - Macrocyclics KW - MALDI KW - Oligomers KW - Polycondensation KW - Thermodynamics PY - 2002 SN - 1022-1352 SN - 1521-3935 IS - 203 SP - 313 EP - 318 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-1656 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grimm, B. A1 - Krüger, Ralph-Peter A1 - Schrader, S. A1 - Prescher, D. T1 - Molecular structure investigations on fluorine containing polyazomethines by means of the MALDI-TOF-MS technique N2 - Three new aromatic polyazomethines have been synthesized by solution polycondensation reactions of terephthalic dialdehyde with fluorine containing aromatic diamines. The polymers were obtained in high yields. The investigation of these polymers by means of matrix-assisted laser desorption ionization–time-of-flight–mass spectrometry (MALDI–TOF–MS) proved the initial members of the four theoretical possible series of the corresponding oligomers with 2–10 repeating units per molecule. KW - Polyazomethines KW - Oligomers KW - MALDI-TOF-MS PY - 2002 DO - https://doi.org/10.1016/S0022-1139(01)00498-5 SN - 0022-1139 SN - 1873-3328 VL - 113 SP - 85 EP - 91 PB - Elsevier CY - Amsterdam AN - OPUS4-1657 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoebbel, D. A1 - Weber, Ch. A1 - Schmidt, H. A1 - Krüger, Ralph-Peter T1 - Synthesis and Properties of Perfluoroalkyl Groups Containing Double Four-Ring Spherosilicate (Siloxysilsesquioxane) Precursors N2 - Organically modified cage-like double four-ring spherosilicates have received considerable interest in the construction of nanosized hybrid materials, as well as building units for structural well-defined polymers. This group is extended by perfluoroalkyl ligands containing spherosilicates, synthesized by addition reaction of the octahydridodimethylsiloxyoctasilsesquioxane [H(CH3)2Si]8Si8O20 and heptadecafluorodecyl methacrylate. The resultant liquid spherosilicate substituted with eight terminal perfluoroalkyl groups was characterized by 29Si and 13C NMR spectroscopies and MALDI Time-of-Flight mass spectrometry. Partial substitution of perfluoroalkyl ligands by trimethoxysilyl containing groups provides condensable precursors for the synthesis of hydrophobic and oleophobic materials via the sol-gel process. This new spherosilicate, carrying on average four perfluoroalkyl groups and four trimethoxysilyl groups shows better hydrophobic and oleophobic properties compared with commonly used perfluoroalkyltrialkoxysilanes under identical concentration of perfluoroalkyl chains. In addition a comprehensive literature survey is given on structural well characterized, organically modified cage-like double four-ring spherosilicates. KW - Spherosilicate KW - Siloxysilsesquioxane KW - Perfluoralkylalkoxysilane KW - 29Si NMR KW - Coatings KW - Hydrophobicity PY - 2002 DO - https://doi.org/10.1023/A:1015239707783 SN - 0928-0707 SN - 1573-4846 VL - 24 SP - 121 EP - 129 PB - Kluwer Academic Publ. CY - Dordrecht AN - OPUS4-1658 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kukula, H. A1 - Schlaad, H. A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana T1 - Improved Synthesis and Characterization of w-Primary Amino-Functional Polystyrenes and Polydienes PY - 2002 DO - https://doi.org/10.1021/ma0204397 SN - 0024-9297 SN - 1520-5835 VL - 35 IS - 18 SP - 7157 EP - 7160 PB - American Chemical Society CY - Washington, DC AN - OPUS4-1659 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter T1 - Determination of functionality and molar mass distribution of aliphatic polyesters by orthogonal liquid chromatography, Part I: Off-line investigation of poly-(1,6-hexanediol adipates) PY - 1994 SN - 0148-3919 VL - 17 SP - 3069 EP - 3090 PB - Dekker CY - New York, NY AN - OPUS4-2139 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter T1 - New Results of Determination of Polymer Heterogeneity by Two-Dimensional Orthogonal Liquid Chromatography T2 - International GPC Symposium CY - Lake Buena Vista, FL, USA DA - 1994-06-05 PY - 1994 SP - 273 EP - 275 PB - Gordon and Breach CY - St. Helier, Jersey AN - OPUS4-2140 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter T1 - Determination of polymer heterogeneity by two-dimensional orthogonal liquid chromatography KW - Orthogonal chromatography KW - Size exclusion chromatography KW - Liquid adsorption chromatography at critical conditions KW - Matrix-assisted laser desorption ionization time-of-flight mass spectrometry KW - Polyester KW - Polyether PY - 1996 SN - 1023-666X SN - 1563-5341 VL - 2 SP - 221 EP - 235 PB - Gordon and Breach Publ. CY - Amsterdam AN - OPUS4-2146 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sonnenschein, H. A1 - Kreher, T. A1 - Gründemann, E. A1 - Krüger, Ralph-Peter A1 - Kunath, A. A1 - Zabel, V. T1 - Novel Redox-Active Cyclophanes Based on 3,3'-Bisindolizines - Synthesis and Chirality PY - 1996 SN - 0022-3263 SN - 1520-6904 VL - 61 SP - 710 EP - 714 PB - American Chemical Society CY - Washington, DC AN - OPUS4-2147 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Leukel, J. A1 - Burchard, W. A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter T1 - Mechanism of the anionic copolymerization of anhydride- cured epoxies-analysisted by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF-MS) PY - 1996 SN - 1022-1336 SN - 1521-3927 VL - 17 SP - 359 EP - 366 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-2148 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter A1 - Wachsen, O. T1 - New aspects of determination of polymer heterogeneity by 2-dimensional orthogonal liquid chromatography and MALDI-TOF-MS PY - 1996 SN - 1022-1360 SN - 0258-0322 SN - 1521-3900 VL - 110 SP - 155 EP - 176 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-2150 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, H.R. A1 - Vakhtangishvili, L. A1 - Schwarz, G. A1 - Schulz, Günter A1 - Krüger, Ralph-Peter T1 - Macrocycles 25. Cyclic poly(ether sulfone)s derived from 4-tert-butylcatechol N2 - Poly(ether sulfone)s were prepared by polycondensation of silylated 4-tert-butylcatechol and 4,4?-difluorodiphenylsulfone in N-methylpyrrolidone. The feed ratio and the reaction time were varied to study the influence of stoichiometry and conversion on molecular weight and extent of cyclization. Molecular weights and molecular weight distributions (MWD)s were characterized by SEC measurements calibrated with polystyrene. Light scattering confirmed that calibration with polystyrene gives reasonable results and revealed a tendency towards a bimodal MWD for the samples rich in cycles. The MALDI-TOF mass spectrometry indicated that the extent of cyclization increased with higher conversion and with optimization of the stoichiometry. This interpretation was confirmed by 1H NMR endgroup analyses. For the samples with the highest molar masses only mass peaks of cycles were found, which were detectable up to 20 000 Da before and up to 27 000 Da after fractionation. Via the pseudo-high dilution method low molar mass poly(ether sulfone) containing more than 95 mol% of cycles were prepared, and even these low molar mass samples had broad MWDs. DSC measurements indicated that the glass transition temperatures depend on the structure of the endgroups and increase with higher fractions of cycles. KW - Poly(ether sulfone)s KW - Polycondensation KW - MALDI-TOF mass spectrometry PY - 2003 DO - https://doi.org/10.1016/S0032-3861(03)00410-5 SN - 0032-3861 SN - 1873-2291 VL - 44 SP - 4471 EP - 4480 PB - Springer CY - Berlin AN - OPUS4-2623 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, H.R. A1 - Vakhtangishvili, L. A1 - Schwarz, G. A1 - Krüger, Ralph-Peter T1 - Cyclic Hyperbranched Poly(ether ketone)s Derived from 3,5-Bis(4-fluorobenzoyl)phenol N2 - 3,5-Bis(4-fluorobenzoyl)phenol was polycondensed under various reaction conditions. Low molecular weights were obtained (Mn < 8000 Da), and MALDI-TOF mass spectrometry indicated that the chain growth was limited by cyclization. In the best mass spectra the cyclic, hyperbranched poly(ether ketone)s were detectable up to masses around 14 000 Da. When 4,4'-difluordiphenyl sulfone was added, star-shaped polymers having a diphenyl sulfone star center were formed, but cyclization was not completely suppressed. The results were compared to those obtained from "linear polycondensations" based on 4,4'-difluorobenzophenone (DFBP) and 4-tert-butylcatechol or bisphenol A. The poly(ether ketone)s of DFBP had also low molecular weights and contained high fractions of cycles. It is concluded that also in the case of hyperbranched polymers cyclization competes with propagation at any stage of the polycondensation at any concentration. Therefore, the fundamental trend of any "abn" polycondensation is the formation of star-shaped polymers having a cyclic core and hyperbranched star arms. PY - 2003 DO - https://doi.org/10.1021/ma021799x SN - 0024-9297 SN - 1520-5835 VL - 36 SP - 5551 EP - 5558 PB - American Chemical Society CY - Washington, DC AN - OPUS4-2622 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Heinemann, M. A1 - Fritz, H.-G. T1 - Influence of L-Lactide Acidity on the Synthesis of Poly(L-Lactide) by Reactive Extrusion and Special Combined Analytical Concepts for the Characterization of Polylyctides T2 - International Union of Pure and Applied Chemistry (IUPAC), Macro 2004 CY - Paris, France DA - 2004-07-04 PY - 2004 AN - OPUS4-3538 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Krüger, Ralph-Peter T1 - H. Pasch and W. Schrepp "MALDI-TOF Mass Spectrometry of Synthetic Polymers" (Book review) PY - 2004 DO - https://doi.org/10.1002/macp.200400155 SN - 1022-1352 SN - 1521-3935 VL - 205 SP - 1284 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-3567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter A1 - Rikowski, E. T1 - Characterization of Silicon-Polymers by Liquid Chromatography and MALDI-TOF-MS T2 - GDCh-Hauptversammlung in Verbindung mit dem 37. IUPAC Congress CY - Berlin, Germany DA - 1999-08-14 PY - 1999 AN - OPUS4-3547 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Viala, S. A1 - Tauer, K. A1 - Antonietti, M. A1 - Krüger, Ralph-Peter A1 - Bremser, W. T1 - Structural control in radical polymerization with 1,1-diphenylethylene. 1. Copolymerization of 1,1-diphenylethylene with methyl methacrylate N2 - The role of 1,1-diphenylethylene (DPE) in radical emulsion polymerization of methyl methacrylate is investigated. The presence of DPE causes a strong decrease in both the rate of polymerization and the molecular weight. According to the results of structure analysis by means of MALDI-TOF mass spectrometry, UV–vis spectroscopy, and 1H–NMR spectroscopy, DPE is incorporated in the copolymer chain exclusively as a reactive recombinant ?,p-dimer, underlining the peculiar role of DPE in radical polymerizations. KW - Emulsion polymerization KW - 1,1-Diphenylethylene KW - Copolymer structure PY - 2002 DO - https://doi.org/10.1016/S0032-3861(02)00676-6 SN - 0032-3861 SN - 1873-2291 VL - 43 IS - 26 SP - 7231 EP - 7241 PB - Springer CY - Berlin AN - OPUS4-1919 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Schulz, Günter A1 - Heinemann, M. A1 - Hartmann, P. T1 - Characterization of Polyesters and Copolyesters by Coupled Liquid Chromatographic and Spectroscopic Techniques T2 - 11. Internationale Fachtagung Polymerwerkstoffe 2004 CY - Halle (Saale), Germany DA - 2004-09-29 PY - 2004 AN - OPUS4-4339 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Schulz, Günter A1 - Heinemann, M. T1 - Characterization of Polyesters and Copolyesters by Coupled Liquid Chromatographic and Spectroscopic Techniques T2 - Polydays 2004 CY - Potsdam, Germany DA - 2004-10-04 PY - 2004 AN - OPUS4-4341 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klapdohr, S. A1 - Moszner, N. A1 - Kickelbick, G. A1 - Krüger, Ralph-Peter T1 - Investigation of the Structure of Polymerizable Silsesquioxanes by GPC and MALDI-TOF-MS in Relation to their Viscosity N2 - Hydrolytic condensation of different methacrylate groups containing alkoxy silanes yielded resins which showed interesting properties as a matrix for dental composites. For this purpose, resins of low viscosity are desired resulting in composites with a high amount of inorganic fillers. Our investigations demonstrated that the viscosity of the obtained polycondensates was predominantly influenced by the kind of organic spacer between the methacrylate group and the silicon atom. In addition, the viscosity also significantly changed in dependence of the kind of structure units built. NMR spectroscopic investigations as well as size exclusion chromatography (SEC) and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry showed that the formed structures depended both on the kind of catalyst used for hydrolysis/condensation and the bulkiness of the organic substituent at the silicon atom. KW - Nanostructure KW - Sols KW - Polycondensation KW - Silicon compounds KW - Dental PY - 2006 DO - https://doi.org/10.1007/s00706-006-0442-z SN - 0026-9247 SN - 1434-4475 VL - 137 SP - 667 EP - 679 PB - Springer CY - Wien AN - OPUS4-12139 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Rikowski, Eckhard A1 - Schulz, Günter A1 - Friedrich, Jörg Florian ED - Grellmann, W. T1 - Synthesis and Characterisation of Polyhedral Silsesquioxanes with Nanotubular Structures T2 - 23. DVM-Vortrags- und Diskussionstagung "Werkstoffprüfung 2005", DA - 2005-12-01 PY - 2005 SP - 25 EP - 30 PB - DVM AN - OPUS4-11947 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Trathnigg, B. A1 - Maier, B. A1 - Schulz, G. A1 - Krüger, Ralph-Peter A1 - Just, Ulrich T1 - Characterization of Polyethers using different methods: SFC, LAC and SEC with different detectors, and MALDI-TOF-MS PY - 1996 SN - 1022-1360 SN - 0258-0322 SN - 1521-3900 VL - 110 SP - 231 EP - 240 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-11332 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Rikowski, Eckhard A1 - Schulz, Günter A1 - Friedrich, Jörg F. T1 - Synthesis and Characterisation of Polyhedral Silsesquioxanes with Nanotubular Structures T2 - DVM-Tagung "Werkstoffprüfung 2005" CY - Berlin, Germany DA - 2005-12-01 PY - 2005 AN - OPUS4-11793 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, H. A1 - Chatti, S. A1 - Schwarz, G. A1 - Krüger, Ralph-Peter T1 - Macrocycles 27 - Cyclic Aliphatic Polyesters of Isosorbide N2 - Numerous polycondensations of isosorbide and suberoyl chloride or other aliphatic dicarboxylic acid dichlorides were performed with pyridine as a catalyst and HCl acceptor. The reaction conditions were varied to optimize both the molecular weight and the fraction of cyclic oligo- and polyesters. Furthermore, we attempted to obtain the cyclic monomer by catalyzed back-biting degradation of the molten cyclic polyesters above 220 °C in vacuo. The polyesters were characterized by viscosity and size exclusion chromatographic measurements as well as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. In selected cases, mixtures of linear and cyclic polyesters were treated with a hot solution of partially methylated ß-cyclodextrin in methanol. This treatment allowed for a selective extraction of the linear chains up to approximately 5000 Da. KW - Polycondensation KW - Cyclization KW - Isosorbide KW - Polyesters KW - MALDI PY - 2003 DO - https://doi.org/10.1002/pola.10933 SN - 0360-6376 SN - 0887-624X VL - 41 IS - 21 SP - 3414 EP - 3424 PB - Wiley CY - Hoboken, NJ AN - OPUS4-12017 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Klapdohr, S A1 - Moszner, N. A1 - Kickelbick, G. T1 - Structure and Related Properties of Polymerizable Silsesquioxanes as a Matrix for Dental Composites T2 - 13th International Workshop on Sol-Gel Science and Technology CY - Los Angeles, CA, USA DA - 2005-08-21 PY - 2005 AN - OPUS4-10748 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidner, Steffen A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Just, Ulrich T1 - Principle of Two-Dimensional Characterization of Copolymers N2 - Two-dimensional polymer characterization is used for a simultaneous analysis of molar masses and chemical heterogeneities (e.g., end groups, copolymer composition, etc.). This principle is based on coupling of two different chromatographic modes. Liquid adsorption chromatography at critical conditions (LACCC) is applied for a separation according to the chemical heterogeneity, whereas in the second-dimension fractions are analyzed with regard to their molar mass distribution by means of size exclusion chromatography (SEC). Because appropriate standards for a calibration of the SEC are seldom available, matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) was used to substitute the SEC. The LACCC-MALDI MS coupling enables acquiring additional structural information on copolymer composition, which can considerably enhance the performance of this coupled method. KW - MALDI-TOF MS KW - Chromatographie KW - Kopplung PY - 2007 DO - https://doi.org/10.1021/ac062145f SN - 0003-2700 SN - 1520-6882 VL - 79 IS - 13 SP - 4814 EP - 4819 PB - American Chemical Society CY - Washington, DC AN - OPUS4-17722 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Just, Ulrich A1 - Weidner, Steffen A1 - Thünemann, Andreas T1 - Hyphenated liquid-chromatographic, spectroscopic and spectrometric techniques for polymer characterization T2 - Polymerwerkstoffe 2006 CY - Halle (Saale), Germany DA - 2006-09-27 PY - 2006 AN - OPUS4-13808 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -