TY - JOUR A1 - Deußing, G. A1 - Dümichen, Erik A1 - Braun, Ulrike T1 - Der Fänger im Spülgas N2 - Durch die intelligente Anbindung an eine in der GC/MS gängige Extraktionstechnik (SBSE) lassen sich Zersetzungsprodukte der thermogravimetrischen Analyse (TGA) von Polymeren auf effiziente Weise anreichern, anschließend trennen und sicher identifizieren. KW - Polymeranalytik KW - Thermische Extraktion PY - 2015 UR - http://www.laborpraxis.vogel.de/so-erweitern-sie-die-moeglichkeiten-der-tga-a-490995/index2.html UR - https://files.vogel.de/vogelonline/vogelonline/issues/6773.pdf SN - 0344-1733 VL - 39 IS - 6 SP - 24 EP - 27 PB - Vogel Business Media AN - OPUS4-42149 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ressnig, A. A1 - Corbiere, T. A1 - Lunkenbein, T. A1 - Braun, Ulrike A1 - Willinger, M. G. A1 - Antonietti, M. T1 - Decomposition synthesis of tuneable, macroporous carbon foams from crystalline precursors via in situ templating N2 - A flexible, sustainable, one-step thermal decomposition route for the synthesis of hierarchical, heteroatom doped carbon foams is presented. Task-specific semi-organic crystals combine functions for three different purposes: the carbon and heteroatom source, a foaming agent (CO2) and an in situ generable template (NaCl). Insights to the decomposition pathway were gained through FTIR/MS coupled TGA and an ultrafast out-of-furnace heating procedure and the products were analysed with (HR)SEM/TEM, EELS, FTIR, and N2 sorption. The resulting macroporous carbon foams are excellent supports for metallic nanoparticles due to their hierarchical structure, high surface area and tuneable heteroatom contents. This was demonstrated for catalytically active copper or the magnetic CoNi alloy for water purification. KW - macroporous carbon KW - thermal decomposition KW - synthesize heteroatom KW - in situ template (NaCl) PY - 2014 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-318641 DO - https://doi.org/10.1039/c4ta03646h SN - 2050-7496 SN - 2050-7488 VL - 2 IS - 42 SP - 18076 EP - 18081 PB - RSC CY - London [u.a.] AN - OPUS4-31864 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike A1 - Schartel, Bernhard T1 - Decomposition pathways in the pyrolysis zone: A key to understand fire retardancy mechanisms T2 - FRPM07 CY - Bolton, England DA - 2007-07-04 PY - 2007 AN - OPUS4-15051 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kittner, Maria A1 - Eisentraut, Paul A1 - Dittmann, Daniel A1 - Braun, Ulrike T1 - Decomposability versus detectability: First validation of TED‐GC/MS for microplastic detection in different environmental matrices N2 - A fast method for microplastic detection is thermal extraction desorption‐gas chromatography/mass spectrometry (TED‐GC/MS), which uses polymer‐specific thermal decomposition products as marker compounds to determine polymer mass contents in environmental samples. So far, matrix impacts of different environmental matrices on TED‐GC/MS performance had not yet been assessed systematically. Therefore, three solid freshwater matrices representing different aquatic bodies with varying organic matter contents were spiked with a total of eight polymers. Additionally, for the first time, the two biodegradable polymers polybutylene adipate terephthalate (PBAT) and polylactide (PLA) were analysed using TED‐GC/MS. The methodological focus of this work was on detectability, quality of signal formation as well as realisation of quantification procedures and determination of the limit of detection (LOD) values. Overall, TED‐GC/MS allowed the unambiguous detection of the environmentally most relevant polymers analysed, even at low mass contents: 0.02 wt% for polystyrene (PS), 0.04 wt% for the tyre component styrene butadiene rubber (SBR) and 0.2 wt% for polypropylene (PP), polyethylene (PE) and PBAT. Further, all obtained LOD values were increased in all matrices compared to the neat polymer without matrix. The LOD of the standard polymers were increased similarly (PS: 0.21–0.34 μg, SBR: 0.27–0.38 μg, PP: 0.32–0.36 μg, PMMA: 0.64–1.30 μg, PET: 0.90–1.37 μg, PE: 3.80–6.99 μg) and their decompositions by radical scission processes were not significantly influenced by the matrices. In contrast, matrixspecific LOD increases of both biodegradable polymers PBAT (LOD: 1.41–7.18 μg) and PLA (0.84–20.46 μg) were observed, probably due to their hetero‐functional character and interactions with the matrices. In conclusion, the TED‐GC/MS performance is not solely determined by the type of the polymers but also by the composition of the matrix. KW - TED-GC/MS KW - Microplastic KW - Freshwater matrices KW - Gas chromatography KW - Mass spectrometry PY - 2023 DO - https://doi.org/10.1002/appl.202200089 SN - 2702-4288 VL - 2 IS - 3 SP - 1 EP - 12 PB - Wiley-VCH CY - Weinheim AN - OPUS4-57419 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike A1 - Dümichen, Erik A1 - Sturm, Heinz T1 - Cure Monitoring Using Infrared Spectroscopy T2 - Wissenschaftskolloquium "Nanotechnologie für Kunststoffverbunde CY - Braunschweig, Germany DA - 2014-09-30 PY - 2014 AN - OPUS4-31584 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Braun, Ulrike A1 - Brademann-Jock, Kerstin A1 - Stark, Wolfgang T1 - Cure monitoring of epoxy films by heatable in situ FTIR analysis: Correlation to composite parts N2 - The curing mechanism of an epoxy film containing dicyandiamide (DICY) and an epoxy formulation based on diglycidyl ether of Bisphenol A (DGEBA) polymer was studied as a function of various temperature programs. The investigation was performed in situ, using a thin film of the epoxy mixture on a silicon wafer substrate in a heatable transmission tool of a FTIR spectrometer. Based on these model-curing experiments, a major curing mechanism was proposed, taking into account the appearance, the decrease, and the development of characteristic bands at various temperatures. The conclusions of the model curing were correlated to FTIR measurements on a real, 50-mm-thick glass fiber reinforced component composite part from a technical process. It could be shown that characteristic bands that develop at curing temperatures above 150°C appear especially in the center of the thick sample. From the chemical or molecular point of view, this demonstrates the established technician's understanding that temperature control inside a large-scale fiber composite of, for example, aircraft, wind-turbine, automotive applications component is of major importance. KW - Crosslinking KW - Resins KW - Spectroscopy KW - Thermosets KW - Thermal properties PY - 2014 DO - https://doi.org/10.1002/APP.39832 SN - 0021-8995 SN - 1097-4628 VL - 131 IS - 3 SP - 39832, 1 EP - 10 PB - Wiley InterScience CY - Hoboken, NJ AN - OPUS4-30716 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Erdmann, Maren A1 - Trappe, Volker A1 - Sturm, Heinz A1 - Braun, Ulrike A1 - Dümichen, Erik T1 - Cure conversion of structural epoxies by cure state analysis and in situ cure kinetics using nondestructive NIR spectroscopy N2 - Non-isothermal heating rate kinetics was applied to two epoxy resin systems. In situ near-infrared (NIR) measurements were taken with a heatable NIR cell which allowed the cure to be monitored by characteristic absorption bands. An autocatalyzed reaction of the nth order was shown to describe the epoxy conversion curves. Differential Scanning Calorimetry (DSC) was used as a complementary method. The kinetic models developed by both NIR and DSC are in good accordance with experimental epoxy conversion in the in situ NIR setup for single and multiple cure temperature ramps. A linear calibration curve of the characteristic absorption bands of epoxy normalized to aromatic vibrations was introduced. The curing degree of structural epoxies that were cured according to an industrial temperature cure profile was determined by NIR using the calibration curve. The epoxy conversions of the structural components showed good agreement with the experimental in situ NIR. Several degrees of cure for structural specimens were evaluated by NIR and residual reaction enthalpy by DSC. We present the non-destructive NIR spectroscopy as an alternative to determine fast and non-destructive epoxy conversion, particularly suitable for high degrees of cure on structural components. KW - Epoxy resin KW - Curing kinetics KW - In situ near-infrared (NIR) spectroscopy KW - Differential scanning calorimetry (DSC) PY - 2017 UR - http://www.sciencedirect.com/science/article/pii/S0040603117300205 DO - https://doi.org/10.1016/j.tca.2017.01.010 SN - 0040-6031 SN - 1872-762X VL - 650 SP - 8 EP - 17 PB - Elsevier B.V. AN - OPUS4-39123 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Braun, Ulrike T1 - Comprehensive fire behaviour assessment of polymeric materials based on cone calorimeter investigations N2 - Bench scale performance based cone calorimeter investigations were conducted on glass fibre reinforced polyamide 66 (PA-66) and high impact polystyrene (HIPS) materials. Red phosphorus and magnesium hydroxide were used as fire retardants. Dilution, heat sink, barrier and charring mechanisms are considered to be active in the condensed phase. Dilution, cooling and flame poisoning mechanisms are discussed for the gas phase. Cone calorimeter data are used to give a comprehensive fire behaviour assessment in terms of the propensity to cause a quick growing fire and of the propensity to cause a fire of long duration. The external heat flux is varied between 30 and 75 kW/m2 so that the results for combustion behaviour and flame retardancy, respectively, are valid for different fire scenarios and fire tests. Results on the intrinsic contribution of the steady heat release rate per unit area reveal information about the flammability behaviour. UL 94 results are predicted in close correspondence to UL 94 experiments. PY - 2003 DO - https://doi.org/10.1515/epoly.2003.3.1.177 SN - 1618-7229 IS - 013 SP - 1 EP - 14 PB - De Gruyter CY - [S.l.] AN - OPUS4-15852 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Elert, Anna Maria A1 - Becker, Roland A1 - Dümichen, Erik A1 - Eisentraut, Paul A1 - Falkenhagen, Jana A1 - Sturm, Heinz A1 - Braun, Ulrike T1 - Comparison of different methods for MP detection: What can we learn from them, and why asking the right question before measurments matters? N2 - In recent years, an increasing trend towards investigating and monitoring the contamination of the environment by microplastics (MP) (plastic pieces < 5 mm) has been observed worldwide. Nonetheless, a reliable methodology that would facilitate and automate the monitoring of MP is still lacking. With the goal of selecting practical and standardized methods, and considering the challenges in microplastics detection, we present here a critical evaluation of two vibrational spectroscopies, Raman and Fourier transform infrared (FTIR) spectroscopy, and two extraction methods: thermal extraction desorption gas chromatography mass spectrometry (TED-GC-MS) and liquid extraction with subsequent size exclusion chromatography (SEC) using a soil with known contents of PE, PP, PS and PET as reference material. The obtained results were compared in terms of measurement time, technique handling, detection limits and requirements for sample preparation. The results showed that in designing and selecting the right methodology, the scientific question that determines what needs to be understood is significant, and should be considered carefully prior to analysis. Depending on whether the object of interest is quantification of the MP particles in the sample, or merely a quick estimate of sample contamination with plastics, the appropriate method must be selected. To obtain overall information about MP in environmental samples, the combination of several parallel approaches should be considered. KW - Microplastics KW - FTIR imaging KW - Raman imaging KW - TED-GC-MS KW - SEC KW - Analysis and identification PY - 2017 DO - https://doi.org/10.1016/j.envpol.2017.08.074 SN - 0269-7491 SN - 1873-6424 VL - 231 IS - 2 SP - 1256 EP - 1264 PB - Elsevier AN - OPUS4-42157 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike A1 - Dümichen, Erik A1 - Barthel, Anne-Kathrin A1 - Bannick, Claus Gerhard T1 - Charakterisierung von Mikroplastik Partikeln aus Umweltproben N2 - Durch den stetig steigenden Einsatz von Plastikprodukten sind unerwünschte Kunststofffunde in verschiedenen Umweltmatrices mittlerweile allgegenwärtig. Besonderes Interesse erfahren die Kunststoffpartikel von einer Größe kleiner 5 mm, sogenannte Mikroplastik (MP) Partikel. Es werden aktuell Risiken für Mensch und Umwelt diskutiert, die von diesen Partikeln ausgehen. T2 - Wasser 2016 - Jahrestagung der Wasserchemischen Gesellschaft CY - Bamberg, Deutschland DA - 02.05.2016 KW - Mikroplastik KW - Polymere KW - Polyethylen (PE) KW - Polystyrol (PS) KW - Poly(ethylenterephthalat) (PET) PY - 2016 SN - 978-3-936028-94-2 SP - 74 EP - 76 PB - Wasserchemische Gesellschaft CY - Mülheim an der Ruhr, Germany AN - OPUS4-36782 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike A1 - Dümichen, Erik A1 - Barthel, Anne-Kathrin A1 - Bannick, Claus Gerhard T1 - Charakterisierung von Mikroplastik Partikeln aus Umweltproben N2 - Durch den stetig steigenden Einsatz von Plastikprodukten sind unerwünschte Kunststofffunde in verschiedenen Umweltmatrices mittlerweile allgegenwärtig. Besonderes Interesse erfahren die Kunststoffpartikel von einer Größe kleiner 5 mm, sogenannte Mikroplastik (MP) Partikel und deren ausgehende Risiken auf Mensch und Umwelt T2 - Wasser 2016 - Jahrestagung der Wasserchemischen Gesellschaft CY - Bamberg, Germany DA - 02.05.2016 KW - Mikroplastik KW - Polymere PY - 2016 AN - OPUS4-36785 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klöckner, P. A1 - Seiwert, B. A1 - Eisentraut, Paul A1 - Braun, Ulrike A1 - Reemtsma, T. A1 - Wagner, S. T1 - Characterization of tire and road wear particles from road runoffindicates highly dynamic particle properties N2 - Tire and road wear particles (TRWPs) are heteroagglomerates of tire rubber and other particles deposited on the road surface and one of the main contributors to non-exhaust emissions of automobile traffic. In this study, samples from road environments were analyzed for their TRWP contents and concentra- tions of eight organic tire constituents. TRWP concentrations were determined by quantifying Zn in the density fraction < 1.9 g/cm ³and by thermal extraction desorption-gas chromatography-mass spectrometry (TED-GC/MS) and the concentrations ranged from 3.7 to 480 mg TRWP/g. Strong and statistically signif- icant correlations with TRWPs were found for 2-hydroxybenzothiazole and 2-aminobenzothiazole, indi- cating that these substances may be suitable markers of TRWPs. The mass distribution of TRWPs in road dust suggests that the main mass fraction formed on roads consists of coarse particles ( > 100 μm). Data for a sedimentation basin indicate that the fine fraction ( < 50 μm) is preferentially transported by road runoffinto receiving waters. The size distribution and density data of TRWP gathered by three different quantitation approaches also suggest that aging of TRWPs leads to changes in their particle density. An improved understanding of the dynamics of TRWP properties is essential to assess the distribution and dissipation of this contaminant of emerging concern in the environment. KW - Tire Wear KW - Density separation KW - Microplastic KW - Urban PY - 2020 DO - https://doi.org/10.1016/j.watres.2020.116262 VL - 185 SP - 116262 PB - Elsevier Ltd. AN - OPUS4-51256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Seefeldt, Henrik A1 - Braun, Ulrike T1 - Burning behavior of wood-plastic composite decking boards in end-use conditions: the effects of geometry, material composition, and moisture N2 - In this study, we investigated the basic knowledge necessary to develop flame-retarded wood–plastic composite (WPC) materials by focusing on decking boards. Therefore, the respective effects of geometry, material composition, and moisture were studied by performing cone calorimetric measurements. Using hollow-shaped geometries removes combustible material and reduces the fire load but simultaneously increases fire propagation. The best results were achieved by using high-wood contents. The addition of talc can reduce the intensity of burning. Moisture also has a positive effect on burning behavior. Apart from the well-known mechanism of water, a change was observed in the resultant residue. KW - WPC KW - Wood-plastic composite KW - Cone calorimeter KW - Decking boards PY - 2012 DO - https://doi.org/10.1177/0734904111423488 SN - 0734-9041 SN - 1530-8049 VL - 30 IS - 1 SP - 41 EP - 54 PB - Sage CY - London AN - OPUS4-25357 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Topolniak, Ievgeniia A1 - Hodoroaba, Vasile-Dan A1 - Pfeifer, Dietmar A1 - Braun, Ulrike A1 - Sturm, Heinz T1 - Boehmite Nanofillers in Epoxy Oligosiloxane Resins: Influencing the Curing Process by Complex Physical and Chemical Interactions N2 - In this work, a novel boehmite (BA)-embedded organic/inorganic nanocomposite coating based on cycloaliphatic epoxy oligosiloxane (CEOS) resin was fabricated applying UV-induced cationic polymerization. The main changes of the material behavior caused by the nanofiller were investigated with regard to its photocuring kinetics, thermal stability, and glass transition. The role of the particle surface was of particular interest, thus, unmodified nanoparticles (HP14) and particles modified with p-toluenesulfonic acid (OS1) were incorporated into a CEOS matrix in the concentration range of 1–10 wt.%. Resulting nanocomposites exhibited improved thermal properties, with the glass transition temperature (Tg) being shifted from 30 °C for unfilled CEOS to 54 °C (2 wt.% HP14) and 73 °C (2 wt.% OS1) for filled CEOS. Additionally, TGA analysis showed increased thermal stability of samples filled with nanoparticles. An attractive interaction between boehmite and CEOS matrix influenced the curing. Real-time infrared spectroscopy (RT-IR) experiments demonstrated that the epoxide conversion rate of nanocomposites was slightly increased compared to neat resin. The beneficial role of the BA can be explained by the participation of hydroxyl groups at the particle surface in photopolymerization processes and by the complementary contribution of p-toluenesulfonic acid surface modifier and water molecules introduced into the system with nanoparticles. KW - Real-time infrared spectroscopy KW - Boehmite KW - Nanocomposite KW - Cationic photocuring KW - Cycloaliphatic epoxy oligosiloxane KW - Epoxy conversion degree PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-479628 DO - https://doi.org/10.3390/ma12091513 VL - 12 IS - 9 SP - 1513 PB - MDPI AN - OPUS4-47962 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike T1 - Beständigkeit von Polymeren: Verständnis molekularer Mechanismen T2 - JKU, Institute of Polymeric Materials and Testing, Seminar lecture CY - Linz, Austria DA - 2013-05-29 PY - 2013 AN - OPUS4-28603 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike T1 - Beständigkeit von Polymeren: Aushärtungs- und Degradationskontrolle T2 - Workshop am Fraunhofer CSP CY - Halle (Saale), Germany DA - 2012-11-06 PY - 2012 AN - OPUS4-26917 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike T1 - Beständigkeit von Medizinprodukten T2 - Life Science Day 2012 CY - Berlin, Germany DA - 2012-06-08 PY - 2012 AN - OPUS4-26013 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schartel, Bernhard A1 - Bartholmai, Matthias A1 - Braun, Ulrike ED - Le Bras, M. T1 - Barrier effects for the fire retardancy of polymers T2 - 9th European Meeting on Fire Retardancy and Protection of Materials CY - Lille, France DA - 2003-09-15 KW - Fire retardancy KW - Nanocomposites KW - Red Phosphorus KW - Mg(OH)2 KW - Cone Calorimeter KW - LOI PY - 2005 SN - 0-85404-582-1 VL - 9 SP - 264 EP - 275 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-7377 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dümichen, Erik A1 - Eisentraut, Paul A1 - Celina, M. A1 - Braun, Ulrike T1 - Automated thermal extraction-desorption gas chromatography mass spectrometry: A multifunctional tool for comprehensive characterization of polymers and their degradation products N2 - The TED-GC-MS analysis is a two-step method. A sample is first decomposed in a thermogravimetric analyzer (TGA) and the gaseous decomposition products are then trapped on a solid-phase adsorber. Subsequently, the solid-phase adsorber is analyzed with thermal desorption gas chromatography mass spectrometry (TDU-GC-MS). This method is ideally suited for the analysis of polymers and their degradation processes. Here, a new entirely automated System is introduced which enables high sample throughput and reproducible automated fractioned collection of decomposition products. Strengths and limitations of the system configuration are elaborated via three examples focused on practical challenges in materials analysis and identification: i) separate analysis of the components of a wood-plastic-composite material, ii) quantitative determination of weight concentration of the constituents of a polymer blend and iii) quantitative analysis of model samples of microplastics in suspended particulate matter. KW - Thermal extraction-desorption gas chromatography mass spectrometry KW - Analysis KW - Polymers KW - Microplastics KW - Automation PY - 2019 DO - https://doi.org/10.1016/j.chroma.2019.01.033 VL - 1592 SP - 133 EP - 142 PB - Elsevier CY - Amsterdam AN - OPUS4-48287 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wesch, Ch. A1 - Elert, Anna Maria A1 - Wörner, M. A1 - Braun, Ulrike A1 - Klein, R. A1 - Paulus, M. T1 - Assuring quality in microplastic monitoring: About the value of clean-air devices as essentials for verified data N2 - Avoiding aerial microfibre contamination of environmental samples is essential for reliable analyses when it comes to the detection of ubiquitous microplastics. Almost all laboratories have contamination problems which are largely unavoidable without investments in clean-air devices. Therefore, our study supplies an approach to assess background microfibre contamination of samples in the laboratory under particle-free air conditions. We tested aerial contamination of samples indoor, in a mobile laboratory, within a laboratory fume hood and on a clean bench with particles filtration during the examining process of a fish. The used clean bench reduced aerial microfibre contamination in our laboratory by 96.5%. This highlights the value of suitable clean-air devices for valid microplastic pollution data. Our results indicate, that pollution levels by microfibres have been overestimated and actual pollution levels may be many times lower. Accordingly, such clean-air devices are recommended for microplastic laboratory applications in future research work to significantly lower error rate KW - Microplastics KW - FTIR KW - Quality KW - Environmental Science KW - Biological techniques PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-412402 DO - https://doi.org/10.1038/s41598-017-05838-4 SN - 2045-2322 VL - 7 SP - Article 5424, 1 EP - 8 PB - Nature AN - OPUS4-41240 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dümichen, Erik A1 - Braun, Ulrike A1 - Senz, R. A1 - Fabian, G. A1 - Sturm, Heinz T1 - Assessment of a new method for the analysis of decomposition gases of polymers by a combining thermogravimetric solid-phase extraction and thermal desorption gas chromatography mass spectrometry N2 - For analysis of the gaseous thermal decomposition products of polymers, the common techniques are thermogravimetry, combined with Fourier transformed infrared spectroscopy (TGA–FTIR) and mass spectrometry (TGA–MS). These methods offer a simple approach to the decomposition mechanism, especially for small decomposition molecules. Complex spectra of gaseous mixtures are very often hard to identify because of overlapping signals. In this paper a new method is described to adsorb the decomposition products during controlled conditions in TGA on solid-phase extraction (SPE) material: twisters. Subsequently the twisters were analysed with thermal desorption gas chromatography mass spectrometry (TDS–GC–MS), which allows the decomposition products to be separated and identified using an MS library. The thermoplastics polyamide 66 (PA 66) and polybutylene terephthalate (PBT) were used as example polymers. The influence of the sample mass and of the purge gas flow during the decomposition process was investigated in TGA. The advantages and limitations of the method were presented in comparison to the common analysis techniques, TGA–FTIR and TGA–MS. KW - TDS-GC-MS KW - TGA-FTIR KW - TGA-MS KW - Degradation KW - Polymer KW - Solid-phase extraction PY - 2014 DO - https://doi.org/10.1016/j.chroma.2014.05.057 SN - 0021-9673 VL - 1354 SP - 117 EP - 128 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-31046 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wawrzyn, Eliza A1 - Schartel, Bernhard A1 - Ciesielski, M. A1 - Kretzschmar, B. A1 - Braun, Ulrike A1 - Döring, M. T1 - Are novel aryl phosphates competitors for bisphenol A bis(diphenyl phosphate) in halogen-free flame-retarded polycarbonate/acrylonitrile-butadiene-styrene blends? N2 - The reactivity of the flame retardant and its decomposition temperature control the condensed-phase action in bisphenol A polycarbonate/acrylonitrile–butadiene–styrene/polytetrafluoroethylene (PC/ABSPTFE) blends. Thus, to increase charring in the condensed phase of PC/ABSPTFE + aryl phosphate, two halogen-free flame retardants were synthesized: 3,3,5-trimethylcyclohexylbisphenol bis(diphenyl phosphate) (TMC-BDP) and bisphenol A bis(diethyl phosphate) (BEP). Their performance is compared to bisphenol A bis(diphenyl phosphate) (BDP) in PC/ABSPTFE blend. The comprehensive study was carried out using thermogravimetry (TG); TG coupled with Fourier transform infrared spectrometer (TG-FTIR); the Underwriters Laboratory burning chamber (UL 94); limiting oxygen index (LOI); cone calorimeter at different irradiations; tensile, bending and heat distortion temperature tests; as well as rheological studies and differential scanning calorimeter (DSC). With respect to pyrolysis, TMC-BDP works as well as BDP in the PC/ABSPTFE blend by enhancing the cross-linking of PC, whereas BEP shows worse performance because it prefers cross-linking with itself rather than with PC. As to its fire behavior, PC/ABSPTFE + TMC-BDP presents results very similar to PC/ABSPTFE + BDP; the blend PC/ABSPTFE + BEP shows lower flame inhibition and higher total heat evolved (THE). The UL 94 for the materials with TMC-BDP and BDP improved from HB to V0 for specimens of 3.2 mm thickness compared to PC/ABSPTFE and PC/ABSPTFE + BEP; the LOI increased from around 24% up to around 28%, respectively. BEP works as the strongest plasticizer in PC/ABSPTFE, whereas the blends with TMC-BDP and BDP present the same rheological properties. PC/ABSPTFE + TMC-BDP exhibits the best mechanical properties among all flame-retarded blends. KW - Polycarbonate (PC) KW - Aryl phosphate KW - Flame retardancy KW - Pyrolysis KW - PC/ABS PY - 2012 DO - https://doi.org/10.1016/j.eurpolymj.2012.06.015 SN - 0014-3057 SN - 1873-1945 VL - 48 IS - 9 SP - 1561 EP - 1574 PB - Elsevier CY - Oxford AN - OPUS4-26292 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dümichen, Erik A1 - Javdanitehran, M. A1 - Erdmann, Maren A1 - Trappe, Volker A1 - Sturm, Heinz A1 - Braun, Ulrike A1 - Ziegmann, G. T1 - Analyzing the network formation and curing kinetics of epoxy resins by in situ near-infrared measurements with variable heating rates N2 - Near-infrared spectroscopy (NIR) turned out to be well suited for analyzing the degree of cure for epoxy systems. In contrast to dynamic scanning calorimetry (DSC), where the released heat of reaction determines the degree of epoxy conversion indirectly, NIR spectroscopy is able to determine the conversion directly by analyzing structural changes. Therefore, a new heatable NIR cell was equipped with an integrated thermocouple, which enables the real sample temperature to be controlled and monitored in situ during epoxy curing. Dynamic scans at different heating rates were used for kinetic modelling, to define kinetic parameters and to predict real curing processes. The kinetic models and their parameters were validated with an isothermal and a more complex multi-step curing scenario. Two available commercial epoxy systems based on DGEBA were used with an anhydride and with an amine hardener. NIR results were compared with DSC data. The simulated conversion predicted with a model fitted on the basis of NIR and DSC dynamic scans showed good agreement with the conversion measured in the isothermal curing validation test. Due to the proven reliability of NIR in measuring the reaction progress of curing, it can be considered a versatile measurement system for in situ monitoring of component production in the automotive, aerospace and wind energy sectors. KW - Epoxy resins KW - Curing kinetics KW - Near-infrared spectroscopy KW - DSC PY - 2015 DO - https://doi.org/10.1016/j.tca.2015.08.008 SN - 0040-6031 SN - 1872-762X VL - 616 SP - 49 EP - 60 PB - Elsevier CY - Amsterdam AN - OPUS4-34187 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike A1 - Eisentraut, Paul A1 - Dümichen, E. T1 - Analytik von Mikroplastik mittels Thermoextraktion Desorption Gas Chromatographie Massen Spektrometrie (TED-GC-MS): Nun auch die Luft? N2 - Der Vortrag gibt eine Überblick über die Messung von Mikroplastik mittels TED-GC-MS mit speziellem Fokus auf Luftgetragene Partikel T2 - Odour and Emissions of Plastic Materials CY - Kassel, Germany DA - 19.03.2019 KW - Mikroplastik KW - Standarisierung KW - Analytik PY - 2019 AN - OPUS4-47583 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike T1 - Analytik von Mikroplastik mittels TED-GC-MS N2 - Der Vortrag stellt spektroskopische und neue thermoanalytische Verfahren zum Nachweis von Mikroplastik dar. Ein spezieller Focus ist auf der Anwendung edr Verfahren für terrestrische Proben. T2 - Fachgespräch Feststoffuntersuchungen 2018 CY - Essen Werden, Germany DA - 05.03.2018 KW - Mikroplastik KW - Analytik KW - GC-MS KW - Thermische Analyse PY - 2018 AN - OPUS4-44525 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike T1 - Analytik von Mikroplastik mit thermo-analytischen Verfahren N2 - Überblick über laufende Ergebnisse zu der Verwendung von Thermo-analytischen Verfahren zum Nachweis von Mikroplastik in komplexen Umweltproben. T2 - 2. Mülheimer Wasseranalytisches Seminar CY - Mülheim, Germany DA - 14.09.2017 KW - Mikroplastik KW - Polymere KW - Thermische Analyse KW - Biogasanlage KW - Klärschlamm PY - 2016 AN - OPUS4-38931 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike A1 - Bannick, C.G. T1 - Analytik von Mikroplastik in komplexen Umweltproben N2 - Der Sachstand zur Analytik von Mikroplastik in Umweltproben wird dargestellt. T2 - Fachausstellung Kunststoffanalytik CY - Lüdenscheid, Germany DA - 04.12.2019 KW - TED-GC-MS KW - Mikroplastik KW - Analytik PY - 2019 AN - OPUS4-50005 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike A1 - Bannick, C.G. T1 - Analytik von Mikroplastik - Verfahren-Ergebnisse-Harmonisierung N2 - Die zunehmenden Nachweise von Kunststoffen in verschiedenen Umweltmedien erfahren in den letzten Jahren weltweit ein zunehmendes wissenschaftliches, gesellschaftliches und politisches Interesse. Besondere Aufmerksamkeit erfahren Kunststoffpartikel von 1-1.000 µm, sogenanntes Mikroplastik. Es wurde mittlerweile in Wasser, Böden, Luft und Biota nachgewiesen. Obwohl die Wirkungen auf die natürlichen Umweltfunktionen noch unklar sind und kontrovers diskutiert werden, ist allein durch die ubiquitäre Präsenz eine systematische Erfassung von Eintragsquellen und Verbleib der Partikel über alle Umweltmedien notwendig, um Maßnahmen zur Reduktion der Einträge zu veranlassen. Für eine zuverlässige Erfassung sind medienübergreifende Verfahren zu entwickeln, welche die drei analytischen Schritte, Probennahme, Probenaufbereitung und Detektion beinhalten. Die Verfahren adressieren unterschiedliche Zielgruppen, welche verschiedene analytische Informationen fordern. Für die akademische Bewertung werden Verfahren mit hohem analytischen Aufwand favorisiert, welche möglichst detaillierte Information über Partikelsorte, -größe, -zahl und -oberflächenbeschaffenheit geben. Im Gegensatz dazu, fordern Anwender aus der Praxis schnelle und einfache Monitoring Verfahren, welche die Bestimmung eines Massengehaltes, bzw. eines Grenzwertes zulassen. Allen ist gemeinsam, dass ein hoher interdisziplinärer Anspruch besteht, der sowohl technische Voraussetzungen zur repräsentativen Probennahme und die Limitationen von Detektionsverfahren berücksichtigt, als auch die Fachkompetenz von Biologen, Umweltwissenschaften, Analytiker und Polymerwissenschaftler einschließt. Verfahren zum Mikroplastiknachweis müssen auch verschieden Proben mit sehr unterschiedlichen Gehalten an natürlicher Matrix gerecht werden. So müssen allein für Wasser Verfahren entwickelt werden, die Mikroplastik verschiedener Form (sphärische Partikel, komplexe Bruchstücke, Fasern) aus Medien mit sehr variablen Partikelanteil (u.a. Trinkwasser, Oberflächenwasser, Abwasser) repräsentativ erfassen, sowie schnell und kostengünstig sind – einschließlich der notwendigen Probenaufbereitung. Die jeweiligen Detektionsverfahren müssen z.B. einzelne Partikel oder integrale Gehalte über drei Dekadenklassen für thermoplastische und insbesondere auch elastomere Partikelsorten erfassen können. T2 - GDCh Wissenschaftsforum CY - Aachen, Germany DA - 15.09.2019 KW - Mikroplastik KW - Analytik KW - TED-GC-MS PY - 2019 AN - OPUS4-49068 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike A1 - Bannick, C.G. T1 - Analytik von Mikroplastik - Verfahren-Ergebnisse-Harmonisierung N2 - Die zunehmenden Nachweise von Kunststoffen in verschiedenen Umweltmedien erfahren in den letzten Jahren weltweit ein zunehmendes wissenschaftliches, gesellschaftliches und politisches Interesse. Besondere Aufmerksamkeit erfahren Kunststoffpartikel von 1-1.000 µm sogenanntes Mikroplastik. Es wurde mittlerweile in Wasser, Böden, Luft und Biota nachgewiesen. Obwohl die Wirkungen auf die natürlichen Umweltfunktionen noch unklar sind und kontrovers diskutiert werden, ist allein durch die ubiquitäre Präsenz eine systematische Erfassung von Eintragsquellen und Verbleib der Partikel über alle Umweltmedien notwendig, um Maßnahmen zur Reduktion der Einträge zu veranlassen. Für eine zuverlässige Erfassung sind medienübergreifende Verfahren zu entwickeln, welche die drei analytischen Schritte, Probennahme, Probenaufbereitung und Detektion beinhalten. Die Verfahren adressieren unterschiedliche Zielgruppen, welche verschiedene analytische Informationen fordern. Für die akademische Bewertung werden Verfahren mit hohem analytischen Aufwand favorisiert, welche möglichst detaillierte Information über Partikelsorte, -größe, -zahl und -oberflächenbeschaffenheit geben. Im Gegensatz dazu, fordern Anwender aus der Praxis schnelle und einfache Monitoring Verfahren, welche die Bestimmung eines Massengehaltes, bzw. eines Grenzwertes zulassen. Allen ist gemeinsam, dass ein hoher interdisziplinärer Anspruch besteht, der sowohl technische Voraussetzungen zur repräsentativen Probennahme und die Limitationen von Detektionsverfahren berücksichtigt, als auch die Fachkompetenz von Biologen, Umweltwissenschaften, Analytiker und Polymerwissenschaftler einschließt. Verfahren zum Mikroplastiknachweis müssen auch verschieden Proben mit sehr unterschiedlichen Gehalten an natürlicher Matrix gerecht werden. So müssen allein für Wasser Verfahren entwickelt werden, die Mikroplastik verschiedener Form (sphärische Partikel, komplexe Bruchstücke, Fasern) aus Medien mit sehr variablen Partikelanteil (u.a. Trinkwasser, Oberflächenwasser, Abwasser) repräsentativ erfassen sowie schnell und kostengünstig sind – einschließlich der notwendigen Probenaufbereitung. Die jeweiligen Detektionsverfahren müssen z.B. einzelne Partikel oder integrale Gehalte über drei Dekadenklassen für thermoplastische und insbesondere auch elastomere Partikelsorten erfassen können. T2 - GDCh Wissenschaftsforum Chemie CY - Aachen, Germany DA - 15.09.2019 KW - TED-GC-MS KW - Mikroplastik KW - Analytik PY - 2019 AN - OPUS4-49995 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike T1 - Analytical opportunities & Challenges in (ocean) microplastics N2 - An overview about the analytical opportunities and challenges in microplastic detection is given. T2 - ISO TC61/ Annual bioplastics & ocean microplastics symposium CY - Chengdu, People's Republic of China DA - 29.09.2019 KW - Harmonisation KW - Microplastics KW - TED-GC-MS PY - 2019 AN - OPUS4-50000 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike T1 - Analytic of microplastics in environmental samples N2 - An overview about the existing possibilities for mircoplastic analysis is given. T2 - 2nd International Symposium on Microplastics CY - Seoul, Korea DA - 02.12.2019 KW - Harmonisation KW - Microplastics KW - TED-GC-MS PY - 2019 AN - OPUS4-50003 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dümichen, Erik A1 - Barthel, Anne-Kathrin A1 - Braun, Ulrike A1 - Bannick, Claus Gerhard A1 - Brand, K. A1 - Jekel, M. A1 - Senz, R. T1 - Analysis of polyethylene microplastics in environmental samples, using a thermal decomposition method N2 - Small polymer particles with a diameter of less than 5 mm called microplastics find their way into the environment from polymer debris and industrial production. Therefore a method is needed to identify and quantify microplastics in various environmental samples to generate reliable concentration values. Such concentration values, i.e. quantitative results, are necessary for an assessment of microplastic in environmental media. This was achieved by thermal extraction in thermogravimetric analysis (TGA), connected to a solid-phase adsorber. These adsorbers were subsequently analysed by thermal desorption gas chromatography mass spectrometry (TDS-GC-MS). In comparison to other chromatographic methods, like pyrolyse gas chromatography mass spectrometry (Py-GC-MS), the relatively high sample masses in TGA (about 200 times higher than used in Py-GC-MS) analysed here enable the measurement of complex matrices that are not homogenous on a small scale. Through the characteristic decomposition products known for every kind of polymer it is possible to identify and even to quantify polymer particles in various matrices. Polyethylene (PE), one of the most important representatives for microplastics, was chosen as an example for identification and quantification. KW - Microplastic KW - Identification and quantification of polymers KW - Thermogravimetric analysis KW - Evolved gas analysis KW - Gas chromatography mass spectroscopy PY - 2015 DO - https://doi.org/10.1016/j.watres.2015.09.002 SN - 0043-1354 VL - 85 SP - 451 EP - 457 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-34337 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike A1 - Dümichen, Erik A1 - Eisentraut, Paul A1 - Barthel, Anne-Kathrin A1 - Bannick, Claus Gerhard T1 - Analysis of microplastic in environmental samples using thermal analytical methods N2 - The presentation addresses first general aspects of polymers and polymers in environment (definitions, types, phases, morphology, density) and than summarise the possibilities of analysis. T2 - Society of Environmental Toxicology and Chemistry Europe CY - Nantes, France DA - 23.05.2016 KW - Microplastics PY - 2016 AN - OPUS4-36900 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike A1 - Dümichen, Erik A1 - Barthel, Anne-Kathrin A1 - Sturm, Heinz A1 - Bannick, Claus Gerhard A1 - Brand, Katrin A1 - Jekel, M. T1 - Analysis of microplastic in environmental samples using thermal analytical methods T2 - ICCE 2015 CY - Leipzig, Germany DA - 2015-09-21 PY - 2015 AN - OPUS4-34528 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Braun, Ulrike A1 - Eisentraut, Paul A1 - Altmann, Korinna A1 - Kittner, Maria A1 - Dümichen, Erik A1 - Thaxton, K. A1 - Kleine-Benne, E. A1 - Anumol, T. T1 - Accelerated Determination of Microplastics in Environmental Samples Using Thermal Extraction Desorption-Gas Chromatography/Mass Spectrometry (TED-GC/MS) N2 - There is growing interest in quantifying microplastics in environmental samples. This application note presents a thermal extraction desorption-gas chromatography/mass spectrometry (TED-GC/MS) method that is well suited to automation and increased sample throughput. The method is also able to detect all particle sizes in the sample as long as the limit of detection (LOD) is reached and allows analysis of larger samples of 15 to 25 mg or more. Samples were decomposed by thermogravimetric analysis (TGA), and the gaseous decomposition products were trapped on a solid-phase sorbent, followed by thermal desorption‑gas chromatography/mass spectrometry (TD-GC/MS) using an Agilent 5977B GC/MSD coupled to an Agilent 7890B GC. Target microplastic particle (MP) polymers were identified in environmental samples including surface water, finished compost, house dust, and drinking water. Quantification of MP polymers in environmental samples provided LODs of 0.06 to 2.2 μg, allowing the detection of MPs in trace amounts with sample weights of up to 1 g. Method repeatability was adequate for reliable quantification with RSDs of approximately 6 to 12%. KW - Environment KW - Microplastic particles KW - TED-GC/MS KW - Mass content KW - Thermoanalytical PY - 2020 VL - 2020 SP - 1 EP - 8 PB - Agilent Technologies Inc. CY - USA AN - OPUS4-51672 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grabmayer, K. A1 - Wallner, G.M. A1 - Beißmann, S. A1 - Braun, Ulrike A1 - Steffen, R. A1 - Nitsche, D. A1 - Röder, B. A1 - Buchberger, W. A1 - Lang, R.W. T1 - Accelerated aging of polyethylene materials at high oxygen pressure characterized by photoluminescence spectroscopy and established aging characterization methods N2 - Two commercial polyethylene grades were exposed to water at elevated temperatures and enhanced oxygen pressure. To characterize their aging behavior laser-induced photoluminescence spectroscopy was applied. Additionally, aging characterization was performed by established methods such as tensile testing, infrared (IR) spectroscopy, high performance liquid chromatography (HPLC), differential scanning calorimetry (DSC) and UV–VIS spectroscopy. During the initial stages of aging, the overall concentration of phenolic antioxidants as well as oxidation onset temperatures decreased exponentially. Simultaneously, significant discoloration due to the formation of conjugated degradation products from phenolic antioxidants (e.g., quinone methides) was detected. After the consumption of antioxidants, photoluminescence started to grow continuously presumably due to the formation of photoluminescent unsaturated carbonyls. In the final stages of aging, embrittlement of the materials as characterized by the degradation of mechanical properties (i.e., loss in ductility) coincided with rising carbonyl index values as well as an increase in crystallinity due to chemicrystallization. Between integrated photoluminescence intensity and carbonyl index, a linear correlation was established. In the induction period, the photoluminescence method exhibited a significantly higher sensitivity to reflect aging induced material changes. KW - Polyethylene KW - PE-RT KW - High oxygen pressure KW - Photoluminescence spectroscopy KW - Aging PY - 2014 DO - https://doi.org/10.1016/j.polymdegradstab.2014.06.021 SN - 0141-3910 SN - 1873-2321 VL - 109 SP - 40 EP - 49 PB - Applied Science Publ. CY - London AN - OPUS4-31349 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, Ulrike T1 - About Standardization and Analytics of Microplastics N2 - Presentation about national and international standardization of microplastic analysis, as well as the project RUSEKU T2 - Industrievereinigung Chemiefaser e.V. CY - Frankfurt, Germany DA - 26.02.2019 KW - Standardisation KW - Microplastic KW - Analysis PY - 2019 AN - OPUS4-47577 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Paul, Andrea A1 - Breitfeld, S. A1 - Sauer, Andreas A1 - Becker, Roland A1 - Kalbe, Ute A1 - Bremser, Wolfram A1 - Braun, Ulrike T1 - A Raman spectroscopic method for the monitoring of microplastics in soil N2 - Due to the increasing presence of microplastic particles (MP) in the Environment and the unknown risks arising from them, there is an urgent need for analytical methods that allow for an efficient identification and quantification of microplastics (MP), i.e. particles < 5 mm, in environmental samples. So far, mostly timeconsuming (micro) infrared or micro-Raman spectroscopic methods are applied. Here an faster alternative Approach is presented based on a Raman processspectrometer with fiber-optical probes in combination with multivariate data analysis. T2 - 12. Kolloquium Prozessanalytik CY - Berlin, Germany DA - 28.11.2016 KW - Raman spectroscopy KW - Microplastics KW - Soil KW - Chemometrics KW - PLS-DA PY - 2016 SP - P10, 59 EP - 60 AN - OPUS4-38392 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wiesner, Yosri A1 - Bednarz, Marius A1 - Braun, Ulrike A1 - Bannick, Claus Gerhard A1 - Ricking, Mathias A1 - Altmann, Korinna T1 - A promising approach to monitor microplastic masses in composts N2 - Inputs of plastic impurities into the environment via the application of fertilizers are regulated in Germany and the EU by means of ordinances. Robust and fast analytical methods are the basis of legal regulations. Currently, only macro- and large microplastic contents (>1 mm) are measured. Microplastics (1–1,000 µm), are not yet monitored. Thermal analytical methods are suitable for this purpose, which can determine the mass content and can also be operated fully automatically in routine mode. Thermal extraction desorption-gas chromatography/mass spectrometry (TED-GC/MS) allows the identification of polymers and the determination of mass contents in solid samples from natural environments. In accordance with the German or European Commission (EC) Fertiliser Ordinance, composting plants should be monitored for microplastic particles with this method in the future. In this context a compost plant was sampled. At the end of the rotting process, the compost was sieved and separated in a coarse (>1 mm) and a fine fraction (<1 mm). The fine fraction was processed using density separation comparing NaCl and NaI as possible salt alternative and screened for microplastic masses by TED-GC/MS with additional validation and quality assurance experiments. With TED-GC/MS total microplastics mass contents of 1.1–3.0 μg/mg in finished compost could be detected with polyethylene mainly. What differs much to the total mass of plastics in the coarse fraction with up to 60 μg/mg, which were visually searched, identified via ATR-FTIR and gravimetrically weighted. KW - Microplastics KW - TED-GC/MS KW - Compost KW - Monitoring KW - Soil PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-586688 DO - https://doi.org/10.3389/fenvc.2023.1281558 SN - 2673-4486 VL - 4 SP - 1 EP - 12 PB - Frontiers Media CY - Lausanne AN - OPUS4-58668 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dümichen, Erik A1 - Braun, Ulrike A1 - Sturm, Heinz A1 - Kraemer, R. A1 - Deglmann, P. A1 - Gaan, S. A1 - Senz, R. T1 - A new molecular understanding of the thermal degradation of PA 66 doped with metal oxides: Experiment and computation N2 - The thermal molecular degradation of polyamide 66 (PA 66) doped with (partially supported) metal oxide particles (Fe2O3, ZnO, Al2O3) was investigated qualitatively and quantitatively using common analysis techniques like thermogravimetry coupled with IR-spectroscopic evolved gas analysis (TGA-FTIR). Using pyrolysis coupled with gas chromatography mass spectrometry (Py-GC-MS), qualitative conclusions were drawn about the complex hydrocarbon products. However, the combination of TGA with solid-phase extraction, followed by thermal desorption gas chromatography mass spectrometry (TED-GC-MS), allows qualitative and even semi-quantitative conclusions about the decomposition pathway of PA 66 in the presence of various metal oxide particles. The investigations under inert conditions showed that the presence of metal particles increases the rate of decarboxylation and deamination reactions, as well as the formation rate of cyclopentanone and pyridine derivatives. These species are a consequence of various condensation reactions. The condensation reactions release a large amount of water, thus triggering the hydrolysis of PA 66. Molecular thermal degradation mechanisms were developed for the main decomposition as well as for the condensation reactions and supported by quantum chemical calculations. The catalytic effect of the metal oxides in PA 66 increases in the following order: PA 66 = PA 66 – Al2O3 < PA 66 – Fe2O3 < PA 66 – ZnO. KW - PA 66 KW - Metal oxide particles KW - Thermal degradation KW - Solid-phase extraction KW - Molecular modeling PY - 2015 DO - https://doi.org/10.1016/j.polymdegradstab.2015.07.011 SN - 0141-3910 SN - 1873-2321 VL - 120 SP - 340 EP - 356 PB - Elsevier Ltd. CY - London AN - OPUS4-33806 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Seefeldt, Henrik A1 - Braun, Ulrike T1 - A new flame retardant for wood materials tested in wood-plastic composites N2 - A new flame retardant based on an ammonium phosphonate is studied with respect to its thermal decomposition and its mode of action in wood-plastic composites (WPCs). The measurements are carried out by means of fire tests (cone calorimeter) and pyrolysis investigations (thermogravimetry, infrared spectroscopy). The flame retardant acts mainly in the condensed phase by increasing the amount of residue formed by the wood part in the WPC. Additional flame dilution is achieved by the release of water, ammonia and carbon dioxide during the decomposition of the flame retardant. KW - Disflamoll TP LXS 51064 KW - Flame retardance KW - Thermogravimetric analysis (TGA) KW - Wood-plastic composites (WPC) PY - 2012 DO - https://doi.org/10.1002/mame.201100382 SN - 1438-7492 SN - 1439-2054 VL - 297 IS - 8 SP - 814 EP - 820 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-26566 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Goedecke, Caroline A1 - Mülow-Stollin, Ulrike A1 - Hering, S. A1 - Richter, Janine A1 - Piechotta, Christian A1 - Paul, Andrea A1 - Braun, Ulrike T1 - A first pilot study on the sorption of environmental pollutants on various microplastic materials N2 - With the drastic increase in plastic production, the input of plastic particles into the environment has become a recognised problem. Xenobiotics are able to sorb to polymer materials, and this process is further enhanced where they Encounter microplastics (plastic fragments <5 mm). In this work we studied the sorption of metformin, a type-2 diabetes drug, and difenoconazole, a fungicide, onto the virgin polymer materials polyamide (PA), polypropylene (PP), and polystyrene (PS). Additionally, PP was cryo-milled and PA was treated with acid to investigate the influence of an increase in surface area and chemical modification. The material properties were also studied by dynamic scanning calorimetry (DSC), gel permeation chromatography (GPC) and Fourier transform infrared spectroscopy (FTIR). Sorption experiments were performed on the basis of a full factorial design examining the effect of agitation, pH value, and salinity. Experimental results showed that difenoconazole sorbs readily to all microplastics, whereas the more polar analyte metformin did not show any affinity to the materials used. For difenoconazole the governing factor in all cases is agitation, while both pH and salinity exhibited only a slight influence. The modification of polymers leads to enhanced sorption, indicating that an increase in surface area (cryo-milled PP) or inner volume (acid-treated PA) strongly favours adsorption. Moreover, long-term experiments demonstrated that the time until equilibrium is reached depends strongly on the particle size. KW - Difenoconazole KW - Metformin KW - Plastic debris KW - Polymer KW - Dynamic scanning calorimetry PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-402393 DO - https://doi.org/10.4172/2380-2391.1000191 SN - 2380-2391 VL - 4 IS - 1 SP - Article 1000191, 1 EP - 8 PB - Omics International CY - Los Angeles AN - OPUS4-40239 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -