TY - JOUR A1 - Weidner, Steffen A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Just, Ulrich T1 - Principle of Two-Dimensional Characterization of Copolymers JF - Analytical chemistry 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 JF - Monatshefte für Chemie = Chemical monthly 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 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 - 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 - Tagungsband der 23. DVM-Vortrags- und Diskussionstagung "Werkstoffprüfung 2005" 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" 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 - 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 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 - Falkenhagen, Jana T1 - Fortschritte bei der Polylactid-Characterisierung T2 - 9. Kolloquium "MALDI-TOF-MS und synthetische Polymere", BAM 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 - 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 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 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 - 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 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 -