TY - CONF A1 - Weidner, Steffen T1 - Entmischungsphänomene in der MALDI dried-droplet Probenpräparation und deren Vermeidung T2 - Anakon 2015 CY - Graz (Österreich) DA - 2015-03-23 PY - 2015 AN - OPUS4-33053 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scholz, Philipp T1 - Degradation of polyurethanes in various environments – Effects on molecular mass and crosslinking N2 - The increasing application of polyurethanes (PU) in safety relevant sectors (fire protection, insulation, medicine technique) requires detailed knowledge of the stability and reliability of these materials. Different climate factors are supposed to induce diverse and overlapping degradation reactions. The knowledge of these degradation mechanisms is necessary for an estimation of the period of application depending on usage of the material. An essential property of a polymeric system is represented by the molecular weight. Since a change of the molecular weight is a measure for the chemical stability of a polymer, size-exclusion chromatography (SEC) was used to monitor changes of the molecular weight of thermoplastic polyether- and polyester urethane (TPU) exposed to thermal, hydrolytic and photo-oxidative (UV) degradation conditions for several days. Thermal treatments were performed at elevated temperatures (100 - 200 °C) under oxidative (air) as well as non-oxidative (nitrogen) conditions to evaluate the specific influence of oxygen on the degradation. At higher temperatures (≥ 175 °C) a fast decrease of the molecular masses of both PU accompanied by a high degree of crosslinking was found. At lower temperatures (≤ 150 °C) the polymers remained widely unaffected by thermal degradation within the investigated degradation interval of up to two weeks, which was already known from FTIR spectroscopy[1]. In contrast to that, UV treatment at 25 °C at less than 10 % rel. humidity (RH) resulted in a fast crosslinking, whereas the molecular masses of both PU decreased slower than during the thermal treatments. The depth of penetration of the UV radiation was determined using 3D printed PU samples with different thicknesses. Hydrolysis based degradation effects were less significant. Only slight molecular mass changes were detected at temperatures ≤ 80 °C within a time span of 14 days, while no crosslinking could be measured. Considering the degradation results at the investigated exposure parameters, it could be shown that ester-based PU in general exhibits a significant higher stability compared to ether-based materials. T2 - ANAKON 2019 CY - Münster, Germany DA - 25.03.2019 KW - Polyurethane KW - Thermal degradation KW - UV degradation KW - Molecular masses KW - Crosslinking PY - 2019 AN - OPUS4-47957 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Charakterisierung von synthetischen Polymeren mit komplexen Strukturen durch HPLC / MALDI-MS-Kopplung T2 - Makromolekulares Kolloquium, DKI CY - Darmstadt, Germany DA - 2002-07-05 PY - 2002 AN - OPUS4-1799 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter 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 - Falkenhagen, Jana T1 - Polylactidanalytik T2 - Fachgruppenvollversammlung BAM CY - Berlin, Germany DA - 2002-01-29 PY - 2002 AN - OPUS4-2192 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - MALDI/MS - A New Technique in Characterizing Chemical Heterogeneity of Degradation Products of Poly(Ethylene Terephthalate)s T2 - International GPC Symposium '96 CY - San Diego, CA, USA DA - 1996-09-08 PY - 1996 AN - OPUS4-11125 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Möglichkeiten zur Polymercharakterisierung durch die Anwendung verschiedener HPLC-Modi in Kopplung mit der MALDI-TOF-MS T2 - WGE Polymertreffen 1999 CY - Potsdam, Germany DA - 1999-05-06 PY - 1999 AN - OPUS4-11129 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - New Aspects of Characterization of Polymer Structures by Coupling of Different HPLC Modes with MALDI-TOF-MS T2 - Workshop on Mass Spectrometry of Polymers CY - Catania, Italy DA - 1999-12-01 PY - 1999 AN - OPUS4-11132 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Investigations of Polymer Structures Using Chromatographic and Spectroscopic Techniques T2 - Esparation and Characterization of Macromolecules CY - Bratislava, Slovakia DA - 1999-07-04 PY - 1999 AN - OPUS4-11131 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - LC-MALDI Coupling for "quantitative" Analysis of Polymers T2 - NIST CY - Gaithersburg, MD, USA DA - 2002-11-06 PY - 2002 AN - OPUS4-11138 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -