TY - JOUR A1 - Leng, Jing A1 - Purohit, Purv A1 - Kang, N. A1 - Wang, D.-Y. A1 - Falkenhagen, Jana A1 - Emmerling, Franziska A1 - Thünemann, Andreas A1 - Schönhals, Andreas T1 - Structure-property relationships of nanocomposites based on polylactide and MgAl layered double hydroxides N2 - Nanocomposites based on poly(ʟ-lactide) (PLA) and organically modified MgAl Layered Double Hydroxides (MgAl-LDH) were prepared by melt blending and investigated by a combination of Differential Scanning Calorimetry (DSC), Small- and Wide-Angle X-ray Scattering (SAXS, WAXS), and dielectric spectroscopy (BDS). Scanning microfocus SAXS investigations show that the MgAl-LDH is homogeneously distributed in the matrix as stacks of 6 layers and/or partly exfoliated layers. DSC and WAXS show that the degree of crystallinity decreases linearly with the content of LDH. The extrapolation of the dependencies (DSC and WAXS) to zero estimates a limiting concentration of LDH CCri of ca. 21 wt% where the crystallization of PLA is completely suppressed by the nanofiller. The dielectric behavior of neat PLA show two relaxation regions, a β-relaxation at low temperatures related to localized fluctuations and the α-relaxation at higher temperatures due to the dynamic glass transition. The dielectric spectra of the nanocomposites show several additional relaxation processes compared to neat PLA which are discussed in detail. For the nanocomposites around 260 K (ƒ = 1 kHz) an additional process is observed which intensity increases with increasing concentration of LDH. This process is mainly attributed to the exchanged dodecylbenzene sulfonate (SDBS) molecules which are adsorbed at the LDH layers and form a mixed phase with the polymer close to the layers and stacks. An analysis of this process provides information about the molecular dynamics in the interfacial region between the LDH layers and the PLA matrix which reveal glassy dynamics in this region. In the temperature range around 310 K (ƒ = 1 kHz) a further process is observed. Its relaxation rate has an unusual saddle-like temperature dependence. It was assigned to rotational fluctuations of water molecules in a nanoporous environment provided by the LDH filler. Above the glass transition temperature a further process is observed at temperatures above. It is related to Maxwell/Wagner/Sillars polarization due to the blocking of charges at the nanofiller. KW - Polymer based nanocomposites KW - Polylactide KW - Layered double hydroxides KW - Dielectric spectroscopy PY - 2015 DO - https://doi.org/10.1016/j.eurpolymj.2015.05.008 SN - 0014-3057 SN - 1873-1945 VL - 68 SP - 338 EP - 354 PB - Elsevier CY - Oxford AN - OPUS4-33257 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 - Neue Ergebnisse der HPLC/MALDI-TOF-MS - Kopplung zur Charakterisierung von synthetischen Polymeren T2 - Analytica Conference 98 CY - München, Deutschland DA - 1998-04-21 PY - 1998 CY - München AN - OPUS4-2235 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - LC-MS Coupling of synthetic polymers - 30 years after John B. Fenn T2 - Int. Symp. on the Sep. and Charact. of Natural and Synthetic Macromolecules (SCM-7) CY - Amsterdam, The Netherlands DA - 2015-01-27 PY - 2015 AN - OPUS4-32503 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Developments in Copolymer Characterization by chromatographic and spectroscopic techniques T2 - Pregl Colloquium at the National Institute of Chemistry, Slovenia CY - Ljubljana, Slovenia DA - 2013-10-16 PY - 2013 AN - OPUS4-29328 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Polymer Characterization by Multidimensional Techniques T2 - Analysis and Characterization of Polymers CY - Toulouse, France DA - 2015-09-07 PY - 2015 AN - OPUS4-34108 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Biobased and biogegradable polymers: Analytical challenges N2 - The variability and heterogeneity in their structural composition is significant for nearly all synthetic and natural polymers. Beside molar mass also functionality type distribution, copolymer composition distribution and architectural features are responsible for changing the material properties. A wide range of analytical techniques are available to get insight into these parameters. However, in most cases it is essential to combine different sophisticated techniques to get closer to actual structures and to avoid statistical averages. Different liquid chromatographic separation modes and their coupling in a two-dimensional way (SEC, LCCC, HILIC, 2D-LC) in combination with suitable detection techniques (e.g. UV, RI, LS, IR, MALDI/ESI-MS) as well as techniques like BET, DCS, SEM/TEM were applied to make structural features visible. A few aspects are discussed for structural different polylactides from various synthesis routes and their behavior in LC-MS. Moreover, some analytical results for technical lignins valorized by mechanochemical treatment or modified by functional polymers are presented. T2 - 10th Intern. Symp. on the Separation and Characterisation of Natural and Synthetic Macromolecules (SCM-10) CY - Amsterdam, Netherlands DA - 01.02.2023 KW - Poly(lactides) KW - Technical lignin PY - 2023 AN - OPUS4-57002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Biobased and biodegradable Polymers: Analytical Challenges N2 - The variability and heterogeneity in their structural composition is significant for nearly all synthetic and natural polymers. Beside molar mass also functionality type distribution, copolymer composition distribution and architectural features are responsible for changing the material properties. A wide range of analytical techniques are available to get insight into these parameters. However, in most cases it is essential to combine different sophisticated techniques to get closer to actual structures and to avoid statistical averages. Different liquid chromatographic separation modes and their coupling in a two-dimensional way (SEC, LCCC, HILIC, 2D-LC) in combination with suitable detection techniques (e.g. UV, RI, LS, IR, MALDI/ESI-MS) as well as techniques like BET, DCS, SEM/TEM were applied to make structural features visible. A few aspects are discussed for structural different polylactides from various synthesis routes and their behavior in LC-MS. T2 - 34th International Symposium on Polymer Analysis and Characterization (ISPAC) CY - Stellenbosch, South Africa DA - 24.04.2023 KW - Biobased polymers KW - Biodegradable polymers KW - Analytical techniques PY - 2023 AN - OPUS4-60002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - A Tribute to Harald –Lignin as biobased polymer-Trends and analytical issues N2 - The presentation includes aspects of material design and characterization with a focus on lignin. Examples are the structural elucidation of lignosulfonates by means of two-dimensional chromatography, the mechanochemical degradation and functionalization of Kraft-Lignin with accompanying analytics. Future projects involving the incorporation of lignin into polymers will be presented. T2 - Farewell Symposium for Prof. Harald Pasch; Polymer Analysis: Advancements in Characterization and Quantification CY - Teltow, Germany DA - 18.03.2024 KW - Lignin KW - Biobased polymers PY - 2024 AN - OPUS4-60003 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fink, Friedrich A1 - Falkenhagen, Jana T1 - From bench to mini – Classification of technical lignins with NIR N2 - Lignin, a by-product of the pulp and paper industry, is the second most abundant biopolymer but remains underutilized due to its complex structure and variability in biomass origin. Classification based on biomass source is crucial for quality assurance and application predictability. This study employs near-infrared (NIR) spectroscopy to classify technical lignins from softwoods, hardwoods, straw, and grasses. Machine learning models (ML), including Support Vector Machines (SVM), Gaussian Process Classification (GPC), Gaussian Naive Bayes (GNB), and Decision Tree Classification (DTC), were developed using spectral preprocessing and principle component analysis (PCA). The models were compared with spectra from handheld and compact spectrometers. Results highlight the potential of NIR spectroscopy and machine learning to enable rapid, reliable lignin classification, paving the way for improved industrial utilization of this abundant resource. T2 - 11th International Symposium on the Separation and Characterization of Natural and Synthetic Macromolecules CY - Amsterdam, The Netherlands DA - 21.01.2025 KW - Lignin KW - Classification KW - Near infrared spectroscopy PY - 2025 AN - OPUS4-62531 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - View into the Depths of Copolymer Microstructure N2 - For different kinds of polymers it will be shown how it could be realized to obtain information on small, sometimes isomeric topological heterogeneities by coupling UPLC / ESI-TOF-MS and LC /MALDI-TOF-MS. T2 - DSM, Fall Meeting CY - Breda, The Netherlands DA - 07.11.2019 KW - Microstructure KW - LC-MS KW - Copolymer PY - 2019 AN - OPUS4-49587 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 - 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 - Falkenhagen, Jana T1 - Synthesis and Characterization of Polyhedral Silsesquioxanes with Nanotubular Structures T2 - DFG-Schwerpunktprogramm "Nanodrähte und Nanoröhren" CY - Bad Honnef, Germany DA - 2004-04-23 PY - 2004 AN - OPUS4-5095 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 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter A1 - Spranger, K. T1 - Neue Möglichkeiten der Polymercharakterisierung durch 2D-HPLC, Kopplung mit spektroskopischen Methoden und MALDI-TOF-MS T2 - Gesellschaft Deutscher Chemiker, "Klassische Polymere im Aufwind, Polymerchemie aktuell" CY - Dresden, Deutschland DA - 1996-03-25 PY - 1996 CY - Dresden AN - OPUS4-2212 LA - deu 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 - Spranger, K. ED - Günther, W. T1 - MALDI-TOF-MS zur Charakterisierung von synthetischen Polymeren in Kopplung mit der HPLC T2 - InCom '96 - International Symposium on Instrumentalized Analytical Chemistry and Computer Technology CY - Düsseldorf, Deutschland DA - 1996-03-25 PY - 1996 PB - IAS CY - Moers AN - OPUS4-2213 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 - JOUR A1 - Falkenhagen, Jana A1 - Much, Helmut A1 - Stauf, W. A1 - Müller, A. H. E. T1 - Characterization of di- and triblock copolymers using coupled chromatogreaphic methods PY - 1999 SN - 0032-3934 VL - 40 IS - 2 SP - 984 EP - 985 PB - American Chemical Society CY - Newark, NJ AN - OPUS4-2183 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Charakterisierung von Polymeren durch Kopplung von flüssigchromatographischen und spektroskopischen Methoden T2 - HPLC-Tage CY - Mannheim, Deutschland DA - 2002-11-12 PY - 2002 AN - OPUS4-1803 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -