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 - 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 - 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 - 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 - CONF A1 - Krüger, Ralph-Peter A1 - Heinemann, M. A1 - Falkenhagen, Jana A1 - Hartmann, A. A1 - Pawlik, K. A1 - Friedrich, Jörg F. A1 - Fritz, H.-G. T1 - Charakterisierung biologisch abbaubarer Homo- und Copolyester T2 - 19. Suttgarter Kunststoff-Kolloquium CY - Stuttgart, Germany DA - 2005-03-09 PY - 2005 AN - OPUS4-7127 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Krüger, Ralph-Peter A1 - Heinemann, M. A1 - Falkenhagen, Jana A1 - Hartmann, A. A1 - Friedrich, Jörg Florian A1 - Fritz, H.-G. ED - Fritz, H. ED - Eisenbach, C. T1 - Charakterisierung biologisch abbaubarer Homo- und Copolyester / Characterisation of biodegradable Homo- and Copolyesters T2 - 19. Stuttgarter Kunststoff-Kolloquium 2005 CY - Stuttgart, Deutschland DA - 2005-03-09 KW - MALDI-TOF-MS KW - Bioabbaubare Polyester KW - Flüssigchromatographie KW - Methodenkopplung KW - Biodegradable polyesters KW - Liquid chromatography KW - Coupling of analytical methods PY - 2005 SN - 3-00-015246-6 SP - 5/P1-1 - 5/P1-9 PB - IKT CY - Stuttgart AN - OPUS4-11767 LA - deu 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 - 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 - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana T1 - Fortschritte bei der Polylactid-Characterisierung T2 - 9. Kolloquium "MALDI-TOF-MS und synthetische Polymere", BAM CY - Berlin, Germany DA - 2005-05-10 PY - 2005 AN - OPUS4-11555 LA - deu 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 - Falkenhagen, Jana A1 - Schulz, Günter A1 - Heinemann, M. A1 - Hartmann, P. T1 - Zur Charakerisierung von bioabbaubaren Polyestern durch Kopplung von chromatographischen Methoden mit der MALDI-Flugzeitmassenspektrometrie T2 - Polydays 2004 CY - Potsdam, Germany DA - 2004-10-04 PY - 2004 AN - OPUS4-5172 LA - deu 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 - Zur Chracterisierung von bioabbaubaren Polyestern durch Kopplung von chromatographischen Methoden mit der MALDI-Flugzeitmassenspektrometrie T2 - 11. Internationale Fachtagung Polymerwerkstoffe 2004 CY - Halle (Saale), Germany DA - 2004-09-29 PY - 2004 AN - OPUS4-3540 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Heinemann, M. A1 - Schulz, Günter T1 - Zur Synthese und Charakterisierung von Polylactiden T2 - Analytica Conference 2004 CY - Munich, Germany DA - 2004-05-11 PY - 2004 AN - OPUS4-3539 LA - deu 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 - 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 - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Schulz, Günter A1 - Heinemann, M. A1 - Hartmann, P. T1 - Zur Charakterisierung von bioabbaubaren Polyestern durch Kopplung von chromatographischen Methoden mit der MALDI-Flugzeitmassenspektrometrie T2 - 11. Internationale Fachtagung Polymerwerkstoffe 2004 CY - Halle (Saale), Germany DA - 2004-09-29 PY - 2004 AN - OPUS4-5158 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Heinemann, M. A1 - Falkenhagen, Jana A1 - Schulz, Günter T1 - Zur Synthese und Characterisierung von Polylactiden T2 - Analytica Conference 2004 CY - Munich, Germany DA - 2004-05-11 PY - 2004 AN - OPUS4-5096 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Heinemann, M. T1 - Fortschritte bei der Polylactidcharacterisierung T2 - Fachgruppenvollversammlung VI.3, BAM CY - Berlin, Germany DA - 2004-12-14 PY - 2004 AN - OPUS4-5536 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gloede, J. A1 - Pieper, U. A1 - Costisella, B. A1 - Krüger, Ralph-Peter T1 - Ein stabiles Trichlor-oxyphosphoran mit einem Oxaphosphorinring N2 - Das cyclische, arylsubstituierte Chlorphosphonit 3 reagiert mit Chlor zum Trichlor-oxyphosphoran 4 (6, 6, 6-Trichlor-6H-dibenzo[c, e]1, 2-oxaphosphorin). Die Stabilität des Phosphorans ist lösungsmittelabhängig. KW - Oxaphosphorines KW - Phosphoranes PY - 2003 DO - https://doi.org/10.1002/zaac.200200360 SN - 0044-2313 SN - 1521-3749 SN - 0372-7874 SN - 0863-1786 SN - 0863-1778 VL - 629 IS - 6 SP - 998 EP - 1000 PB - Wiley-VCH CY - Weinheim AN - OPUS4-2541 LA - deu 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 - 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 - GEN A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Schulz, Günter A1 - Heinemann, M. A1 - Weinmann, S. A1 - Friedrich, Jörg Florian A1 - Fritz, H.-G. ED - Fritz, H.-G. ED - Eisenbach, C. D. T1 - Synthese von Polylactiden mittels reaktiver Extrusion und Produktcharakterisierung durch Kopplung von HPLC-Methoden mit der MALDI-TOF-MS T2 - 18. Stuttgarter Kunststoff-Kolloquium CY - Stuttgart, Deutschland DA - 2003-03-19 PY - 2003 SN - 3-00-010663-4 IS - CD-ROM PB - Univ., IKT, IAMC CY - Stuttgart AN - OPUS4-2190 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Schulz, Günter ED - Jutzi, P. ED - Schubert, U. T1 - Characterization of Si-polymers by coupling of HPLC-separation methods with MALDI-TOF-MS T2 - Symposium on Silicon Chemistry CY - Werfenweng, Österreich DA - 2002-01-01 PY - 2003 SN - 3-527-30647-1 SP - 406 EP - 418 PB - Wiley-VCH CY - Weinheim AN - OPUS4-2194 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Falkenhagen, Jana A1 - Jancke, Harald A1 - Krüger, Ralph-Peter A1 - Rikowski, Eckhard A1 - Schulz, Günter T1 - Characterization of Silsesquioxanes by Size-exclusion chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry N2 - Liquid chromatography in combination with spectroscopic methods like matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) or nuclear magnetic resonance (NMR) spectroscopy is a powerful method to characterize silsesquioxanes and silsesquioxane mixtures. As new examples, the formation of silsesquioxyl-substituted silsesquioxanes [(n-octyl)7(SiO1.5)8]2O and [(n-octyl)7(SiO1.5)8O]2[(n-octyl)6(SiO1.5)8] as well as the cage rearrangement of octa-[(n-heptyl)silsesquioxane] to larger structur es [(n-heptyl)SiO1.5)]n up to n=28 are shown. PY - 2003 DO - https://doi.org/10.1002/rcm.911 SN - 0951-4198 SN - 1097-0231 VL - 17 IS - 4 SP - 285 EP - 290 PB - Wiley CY - Chichester AN - OPUS4-2182 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 - Weinmann, S. A1 - Friedrich, Jörg F. A1 - Fritz, H.-G. T1 - Synthese von Polylactiden mittels reaktiver Extrusion und Produktcharakterisierung durch Kopplung von HPLC-Methoden mit der MALDI-TOF-MS T2 - 18. Stuttgarter Kunststoff-Kolloquium CY - Stuttgart, Germany DA - 2003-03-19 PY - 2003 AN - OPUS4-3101 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Schulz, Günter A1 - Heinemann, M. T1 - Methodenkopplung zur Polylactidcharakterisierung PY - 2003 SN - 0344-1733 SN - 1610-8256 VL - 27 SP - 56 EP - 57 PB - Vogel CY - Würzburg AN - OPUS4-2597 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Schulz, Günter T1 - Fortschritte in der Polylactidanalytik T2 - 7. MALDI-Kolloquium, BAM CY - Berlin, Germany DA - 2003-05-13 PY - 2003 AN - OPUS4-3541 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Janiak, Ch. A1 - Lange, K.C.H. A1 - Marquardt, P. A1 - Krüger, Ralph-Peter A1 - Hanselmann, R. T1 - Analyses of Propene and 1-Hexene Oligomers from Zirconocene/MAO Catalysts - Mechanistic Implications by NMR, SEC and MALDI-TOF MS N2 - A series of Cp(C5H5)ZrCl2 and Cp2ZrCl2 pre-catalysts (Cp = C5HMe4, C4Me4P, C5Me5, C5H4tBu, C5H3-1,3-tBu2, C5H2-1,2,4-tBu3) together with (C5H5)2ZrCl2 was used for the directed oligomerization of propene and 1-hexene in comparative experiments. Oligomer characterization was carried out by 1H NMR, SEC (GPC), MALDI-TOF MS, cryoscopy and Raman spectroscopy. From 1H NMR the nature and relative ratio of the double-bond end group is determined together with n if every oligomer molecule contains such a double-bond end group. Normally vinylidene double bonds (from -hydrogen elimination) are found. From 1H NMR and MALDI-TOF MS also vinyl end groups (from -methyl elimination) are observed in the case of oligopropenes with (C4Me4P)- (C5H5)ZrCl2 and with the symmetrical methyl containing Cp2ZrCl2 pre-catalysts. The vinylidene/vinyl ratio depends on the ligand and increases from C5HMe4 (65/35) over C4Me4P (61/39) to C5Me5 (9/91). A comparison of n from 1H NMR and SEC together with MALDI-TOF MS shows that the phospholyl-zirconocenes and (C5HMe4)2ZrCl2 also exhibit chain transfer to aluminium, thereby giving saturated oligomers. KW - Chain transfer KW - MALDI KW - Metallocene catalysts KW - Oligomers KW - Polyolefins PY - 2002 DO - https://doi.org/10.1002/1521-3935(20020101)203:1<129::AID-MACP129>3.0.CO;2-C SN - 1022-1352 SN - 1521-3935 VL - 203 IS - 1 SP - 129 EP - 138 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-2179 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, H.R. A1 - Böhme, S. A1 - Krüger, Ralph-Peter T1 - Macrocycles, 16a - Macrocyclic Dibutyltin Dicarboxylates via Thermodynamically Controlled Polycondensations 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. KW - Macrocyclics KW - MALDI KW - Oligomers KW - Polycondensation KW - Thermodynamics PY - 2002 SN - 1022-1352 SN - 1521-3935 VL - 203 IS - 2 SP - 313 EP - 318 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-2181 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Schulz, Günter A1 - Weinmann, S. ED - Radusch, H.-J. ED - Fiedler, L. T1 - Beiträge zur Charakterisierung von Polyactiden durch Kopplung von HPLC-Trennmethoden mit der MALDI-Flugzeitmassenspektrometrie T2 - Internationale Fachtagung Polymerwerkstoffe ; P-2002 CY - Halle (Saale), Deutschland DA - 2002-09-25 PY - 2002 SN - 3-86010-656-2 PB - Martin-Luther-Univ. Halle-Wittenberg CY - Halle (Saale) AN - OPUS4-2189 LA - deu 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 - Krüger, Ralph-Peter A1 - Schöch, M. A1 - Müller, G. A1 - Hahne, D.-B. T1 - Strukturuntersuchungen an Makromonomeren für partiell kristalline polymere Netzwerke T2 - Vortragstagung "Funktionspolymere für Systemlösungen" CY - Darmstadt, Germany DA - 2002-03-18 PY - 2002 AN - OPUS4-1806 LA - deu 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 - 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 - 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 - 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 - Polymercharakterisierung durch Kombination chromatographischer Verfahren sowie HPLC - MALDI-TOF-MS - Kopplung T2 - Tagung der BASF AG 2002 CY - Ludwigshafen, Deutschland DA - 2002-12-03 PY - 2002 AN - OPUS4-1804 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Schulz, Günter T1 - Einführung in die MALDI-TOF-Massenspektrometrie an synthetischen Polymeren T2 - Innovent Technologieentwicklung CY - Jena, Deutschland DA - 2002-08-14 PY - 2002 AN - OPUS4-1800 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Schulz, Günter T1 - Mehrdimensionale Analysenverfahren für komplexe Polymere - Arbeitskreis Polymeranalytik T2 - Tagung des Arbeitskreises Polymeranalytik CY - Darmstadt, Deutschland DA - 2002-09-25 PY - 2002 AN - OPUS4-1802 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Schulz, Günter T1 - Polymercharakterisierung mittels flüssigchromatographischer und spektroskopischer Methoden T2 - Innovent Technologieentwicklung CY - Jena, Deutschland DA - 2002-08-14 PY - 2002 AN - OPUS4-1801 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Schulz, Günter T1 - Calixarene in Photoresisten T2 - 6. MALDI-Kolloquium, BAM CY - Berlin, Germany DA - 2002-05-14 PY - 2002 AN - OPUS4-1798 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schulz, Günter A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter T1 - Kopplung von HPLC-Trennmethoden mit der MALDI-TOF-Massenspektrometrie zur Charakterisierung von Si-haltigen Verbindungen T2 - DFG-Symposium zum Schwerpunktprogramm "Silicium-Chemie" CY - Werfenweng, Österreich DA - 2002-05-02 PY - 2002 AN - OPUS4-1797 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Schulz, Günter A1 - Weinmann, S. T1 - Beiträge zur Charakterisierung von Polyactiden durch Kopplung von HPLC-Trennmethoden mit der MALDI-TOF-MS T2 - Analytica Conference 2002 CY - München, Deutschland DA - 2002-04-23 PY - 2002 AN - OPUS4-2188 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Schulz, Günter T1 - Calixarene in Photoresisten (Kopplung von flüssigchromatographischen Methoden mit der MALDI-TOF-MS) T2 - Fachgruppenvollversammlung BAM CY - Berlin, Deutschland DA - 2002-01-29 PY - 2002 AN - OPUS4-2191 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Schulz, Günter A1 - Weinmann, S. T1 - Beiträge zur Charakterisierung von Polylactiden durch Kopplung von HPLC-Trennmethoden mit der MALDI-Flugzeitmassenspektrometrie T2 - Polymerwerkstoffe 2002 CY - Halle (Saale), Germany DA - 2002-09-25 PY - 2002 AN - OPUS4-3387 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -