TY - CONF A1 - Wachtendorf, Volker T1 - Zusammenhang von molekularen Alterungsvorgängen und beobachtbaren Eigenschaftsänderungen bei der Bewitterung von Polymeren T2 - 39. Jahrestagung der Gesellschaft für Umweltsimulation (GUS) CY - Stutensee, Germany DA - 2010-03-17 PY - 2010 AN - OPUS4-21013 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wachtendorf, Volker A1 - Geburtig, Anja T1 - Chemiluminescence for the early detection of weathering effects of coatings - Part II: Experimental set-up and examination KW - Chemiluminescence KW - Weathering KW - Polymer KW - Oxidation PY - 2010 SN - 1547-0083 VL - 7 IS - 5 SP - 38 EP - 44 PB - Federation of Societies for Coatings Technology CY - Blue Bell, Pa. AN - OPUS4-21494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wachtendorf, Volker T1 - Arrhenius-Ansatz zur Lebensdauervorhersage aus künstlichen Bewitterungsversuchen T2 - 41. Jahrestagung der GUS 2012 - Umwelteinflüsse erfassen, simulieren, bewerten CY - Stutensee, Germany DA - 2012-03-14 PY - 2012 AN - OPUS4-25627 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wachtendorf, Volker T1 - CarbonLifeCycle - Weathering Induced Degradation of Nanoparticle-Functionalised Polymers T2 - 5th European Weathering Symposium (EWS) CY - Lisbon, Portugal DA - 2011-09-21 PY - 2011 AN - OPUS4-24424 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wachtendorf, Volker T1 - Development of al leaching test to estimate emissions from synthetic sports grounds into soil and ground water under weathering exposure T2 - [Conference] "Service Life Prediction of Polymeric Materials: Vision for the Future" CY - Monterey, CA, USA DA - 2013-03-03 PY - 2013 AN - OPUS4-27915 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Trubiroha, P. A1 - Zäh, M. A1 - Schönlein, A. A1 - Müller, A. A1 - Vatahska, T. A1 - Manier, G. A1 - Reichert, T. ED - White, C. C. ED - Martin, J. ED - Chapin, J.T. T1 - Polypropylene numerical photoageing simulation by dose-response functions with respect to irradiation and temperature: vipquali project N2 - The aim of the joint project ViPQuali (Virtual Product Qualification) was to describe a component’s ageing behaviour in a given environment, by numerical simulation. Having chosen polypropylene (PP) as the material, which does not show sensitivity to moisture, the relevant weathering parameters of the dose–response functions could be limited to spectral irradiance and temperature. In artificial irradiation tests, for PP plates of varied stabiliser content, spectral sensitivity as well as temperature dependence of irradiation-caused crack formation was quantified. For that purpose, samples were exposed both to artificial weathering tests at various constant temperatures and to spectrally resolved irradiation. The temperature dependence could be modelled by an Arrhenius fit. For fitting the spectral sensitivity, a plateau function was chosen. Subsequently, the stabiliser content was parameterised and extrapolated. The formed dose–response functions were incorporated into a Computational Fluid Dynamics (CFD) software program, simulating the environment of a sample within a Phoenix-exposed IP/DP (Instrument Panel/Door Panel box) box, based on sun position and weather conditions, including radiation interactions. Observed local effects as well as the general ageing advance of PP hats are compared with respect to simulation and experiment. Resulting from this project, for this most simple example of PP of varied stabiliser content, the time to failure can be estimated for each weathering exposure environment with known time-resolved irradiance and temperature conditions. PY - 2015 SN - 978-3-319-06033-0 SN - 978-3-319-06034-7 DO - https://doi.org/10.1007/978-3-319-06034-7_14 SP - Chapter 14, 215 EP - 229 PB - Springer AN - OPUS4-32062 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trubiroha, P. A1 - Geburtig, Anja A1 - Wachtendorf, Volker ED - Reichert, T. T1 - Surface temperatures of irradiated test specimens - decisive physical quantities and a largely unsolved problem N2 - Temperature is an important parameter in weathering tests. In many (photo-)chemical degradation processes a Variation of the specimen temperature by A t = + 1 °C can cause a Variation of AP(property change) by ± 8%. Since the early eighties it is well known that some types of black panel thermometers can show temperatures that are far below the maximum surface temperature of a black specimen. Although, there were precise requirements for the black coating of the BPT, a replacement by a white coating - depending on the design of the BPT - did not really change the temperature shown by the thermometer. There was no correlation between the BPT and the specimen surface temperature. In Europe and later at ISO the so-called black- and white-standard thermometers BST/WST were introduced. Now, there are BST and WST (ISO) and there are thermally uninsulated and insulated BPT and WPT (ASTM), partly for artificial or for outdoor exposure. And there are other adventurous procedures to determine surface temperatures. The different types of thermometers and different procedures will be discussed and it will be shown that there is no procedure which establishes a correlation between outdoor surface temperatures and surface temperatures in artificial exposure tests. T2 - 6th European weathering symposium Natural and artificial ageing of polymers CY - Bratislava, Slovak Republic DA - 11.09.2013 PY - 2013 SN - 978-3-9813136-8-0 N1 - Serientitel: CEEES Publication – Series title: CEEES Publication IS - 16 SP - 185 EP - 194 AN - OPUS4-31292 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trubiroha, P. A1 - Geburtig, Anja A1 - Wachtendorf, Volker ED - Reichert, T. T1 - On the yet unsolved problem of the determination of precise surface temperatures of specimens exposed to natural and artificial weathering N2 - The surface temperature of test specimens exposed to natural and artificial solar radiation are roughly ascertained with black standard thermometers BST and white standard thermometers WST. For the calibration of these thermometers a new European Standard prEN 16465 was published in 2015, describing the well-known contact method and a new contactless method with a pyrometer. It can be confirmed that the temperature calibrations according to the two methods provide different calibration results which are not interchangeable (which is already stated in the scope of this standard). The described contactless method to determine the surface temperature 'under radiation load' results in clearly too high temperatures. This paper tries to highlighting the reasons. T2 - 7th European weathering symposium - Natural and artificial ageing of polymers CY - Naples, Italy DA - 16.09.2015 PY - 2015 SN - 978-3-9816286-6-1 N1 - Serientitel: CEEES Publication – Series title: CEEES Publication IS - 17 SP - 23 EP - 36 AN - OPUS4-34351 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wachtendorf, Volker A1 - Geburtig, Anja T1 - Chancen und Grenzen der Verkürzung von Bewitterungstests durch empfindliche Chemilumineszenz-Detektion N2 - Eine Verkürzung der Dauer von Bewitterungsversuchen kann durch eine empfindlichere Detektion der Bewitterungseffekte erreicht werden als sie konventionell benützt wird. Eine solche besonders empfindliche Detektionsmethode stellt die Chemilumineszenz dar. Die Verkürzung durch empfindliche Detektion muss jedoch gleichzeitig der Bedingung genügen, ausreichend gute Rangkorrelation zu Bewitterungseffekten unter Anwendungsbedingungen zu zeigen. In diesem Spannungsfeld sollen die Möglichkeiten der Chemiluminiszenz-Detektion beleuchtet werden. T2 - DFO Qualitätstage 2008 CY - Fürth, Deutschland DA - 2008-10-07 KW - Chemilumineszenz KW - Bewitterung KW - Verkürzung KW - empfindlicher Nachweis PY - 2008 SN - 978-3-89943-072-1 SP - 105 EP - 120 PB - DFO CY - Fürth AN - OPUS4-18328 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wachtendorf, Volker A1 - Geburtig, Anja ED - Ziegahn, K.-F. T1 - Zusammenhang von molekularen Alterungsvorgängen und beobachtbaren Eigenschaftsänderungen bei der Bewitterung von Polymeren T2 - 39. Jahrestagung der GUS 2010 - Umweltflüsse erfassen, simulieren, bewerten CY - Stutensee, Deutschland DA - 2010-03-17 KW - Bewitterung KW - Alterung KW - Eigenschaftsänderung KW - Korrelation PY - 2010 SN - 978-3-9813136-0-4 SP - 45 EP - 55 PB - DWS Werbeagentur und Verlag GmbH CY - Pfinztal AN - OPUS4-21047 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wachtendorf, Volker A1 - Geburtig, Anja T1 - Untersuchung der Veränderung der Kratzfestigkeit und Reflow-Fähigkeit von Karosserie-Klarlacken als Folge der Auslagerung in Jacksonville und nachgestellter Laborbewitterung T2 - DFO Qualitätstage 2005 - Moderne Verfahren zur Oberflächencharakterisierung CY - Berlin, Deutschland DA - 2005-10-25 KW - Bewitterung KW - Kratzfestigkeit KW - Kratzbeständigkeit KW - Reflow KW - Weißlichtinterferenz KW - Rauhigkeit PY - 2005 SN - 3-89943-062-X SP - 88 EP - 102 PB - DFO CY - Düsseldorf AN - OPUS4-11216 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Geburtig, Anja A1 - Wachtendorf, Volker T1 - Determination of the spectral sensitivity and temperature dependence of polypropylene crack formation caused by UV-irradiation N2 - For polypropylene of varied stabilization, spectral sensitivity as well as temperature dependence of irradiation caused crack formation was determined in artificial irradiation tests. UV radiant exposure HUV necessary to generate crack formation was measured both in spectrally dispersed irradiation and artificial irradiation in a Fluorescent UV lamp device. Dependencies were fitted to a plateau function and an Arrhenius function, respectively, to describe the action of irradiation by response functions. Applied to weather data from Phoenix, the results were compared with respective outdoor exposure results. KW - Weathering KW - UV KW - Temperature KW - Numerical simulation PY - 2010 DO - https://doi.org/10.1016/j.polymdegradstab.2010.06.014 SN - 0141-3910 SN - 1873-2321 VL - 95 IS - 10 SP - 2118 EP - 2123 PB - Applied Science Publ. CY - London AN - OPUS4-21913 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wachtendorf, Volker T1 - Spezifische Witterungsempfindlichkeiten verschiedener Kunststoffe im Außenbereich T2 - SKZ Fachtagung "Bewitterung von Kunststoffen und Lacken" CY - Würzburg, Germany DA - 2009-03-04 PY - 2009 AN - OPUS4-19591 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wachtendorf, Volker A1 - Geburtig, Anja T1 - Chemiluminescence for the early detection of weathering effects of coatings - Part I: Fundamentals KW - Chemiluminescence KW - Weathering KW - Polymer KW - Oxidation PY - 2010 SN - 1547-0083 VL - 7 IS - 4 SP - 66 EP - 71 PB - Federation of Societies for Coatings Technology CY - Blue Bell, Pa. AN - OPUS4-21493 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Lüthi, A. A1 - Fäh, D. A1 - Wachtendorf, Volker A1 - Geburtig, Anja ED - Reichert, T. ED - Halafka, S. T1 - Recent Proposals for Weathering Reference Materials as Discussed by DIN and VDA T2 - 1st European Weathering Symposium (EWS-1) ; 23rd Colloquium of Danubian Countries on Natural and Artificial Ageing of Polymers CY - Prague, Czech Republic DA - 2003-09-25 KW - Reference material KW - ORWET KW - Crack KW - Climatic KW - ADF test KW - Spectral sensitivity KW - Referenzmaterial KW - Riss KW - Klimatische Beständigkeit PY - 2003 SN - 3-9808382-3-4 SP - 1(?) EP - 12(?) PB - Gesellschaft für Umweltsimulation e.V. CY - Pfinztal AN - OPUS4-2682 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wachtendorf, Volker A1 - Geburtig, Anja A1 - Trubiroha, P. T1 - Application of a newly proposed sensor for effective UV-irradiance for the monitoring of both natural and artificial weathering conditions N2 - To improve on the classic radiometric sensor with radiometric measurement [ ] here a new UV-sensor characteristic for effective UV is proposed that no longer applies equal weighting of spectral irradiation into the UV irradiance value but rather aims at approaching a weighting according to a typical spectral sensitivity curve of polymers. This curve resembles the erythema curve of the skin which is the basis of the UV-index. For the use of the sensor it would be desirable to keep it in the artificial weathering device for the complete weathering test (including rain phases) while the same sensor should also be applicable for the monitoring of outdoor weathering exposures. A first application of this kind of weighted measurement and a comparison with radiometric measurements accompanied with polymer ageing results will be presented together with conclusions for a future effective UV irradiance sensor. T2 - 9th European Weathering Symposium CY - Basel, Switzerland DA - 18.09.2019 KW - UV-irradiance PY - 2019 SN - 978-3-9818507-5-8 VL - 19 SP - 293 EP - 306 AN - OPUS4-49154 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wachtendorf, Volker A1 - Barthel, Anne-Kathrin A1 - Geburtig, Anja A1 - Trubiroha, P. ED - Reichert, T. T1 - Low-Temperature Irradiation Experiments for PE, PA, and PC Matrices N2 - In this paper, we demonstrate the effects of radiation exposures of polymeric materials with UV-A 340 nm lamps (ISO 4892-3, Type 1A) at -10 °C in comparison to an irradiation at +50 °C using a Global UV Test 200 fluorescent lamp device from Weiss Umwelttechnik GmbH, which incorporates an active cooling appliance. While the effects at -10 °C actually are lower than at + 50°C their extent was clearly beyond expectations. T2 - 8th European Weathering Symposium CY - Vienna, Austria DA - 20.09.2017 KW - Artificial weathering KW - Irradiation KW - Low-temperature KW - Photo-oxidation KW - Polyamide KW - Polycarbonate KW - Polyethylene PY - 2017 SN - 978-3-9818507-1-0 VL - 18 SP - Paper 22, 319 EP - 329 PB - Thomas Würtz Grafik Design CY - Karlsruhe AN - OPUS4-42130 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Trubiroha, Peter T1 - Two New Weathering Reference Materials - Monitors for Weathering Exposure T2 - 3rd Service Life Symposium CY - Sedona, AZ, USA DA - 2004-02-01 KW - Weathering KW - Reference material KW - WRM KW - UV KW - Radiance KW - Crack KW - JIS K7200 KW - Humidity KW - Bewitterung KW - Referenzmaterial KW - Riss KW - Bestrahlung KW - Luftfeuchte PY - 2005 SN - 0-934010-60-9 SP - 253 EP - 258 PB - Federation of Societies for Coatings Technology CY - Philadelphia AN - OPUS4-13712 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Trubiroha, Peter A1 - Takane, Y. T1 - UV-sensitive Weathering Reference Materials T2 - 2nd European Weathering Symposium - Natural and Artificial Ageing of Polymers CY - Gothenburg, Sweden DA - 2005-06-16 KW - Weathering Reference Materials PY - 2005 SN - 3-9808382-9-3 VL - 6 SP - 145 EP - 154 PB - Gesellschaft für Umweltsimulation CY - Pfinztal AN - OPUS4-10376 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trubiroha, P. A1 - Geburtig, Anja A1 - Wachtendorf, Volker T1 - Messung der Temperatur von bestrahlten Oberflächen-Blechdicke beim BST N2 - Die Grenzen der Oberflächentemperaturen von Proben, die der natürlichen oder einer künstlichen Globalstrahlung ausgesetzt sind, können grob mit sog. Schwarzstandard Thermometern BST oder Weißstandard Thermometern WST ermittelt werden [ 1a) ]. Um einige Mängel der aktuellen Konstruktion zu beseitigen, wird ein neues Konzept dieser Thermometer vorgeschlagen, das sie weniger träge und ihre physikalischen Eigenschaften ähnlicher denen einer 5 mm dicken Polymerplatte macht. Es wird auch gezeigt, dass eine Anforderung an die Reaktionszeit von weniger als 1 min in EN 513 unrealistisch ist. T2 - 45. Jahrestagung der GUS CY - Stutensee DA - 16.03.2016 KW - Oberflächentemperatur KW - Strahlungserwärmung KW - IR-Thermometer PY - 2016 SN - 978-3-9816286-7-8 SP - 125 EP - 134 AN - OPUS4-36916 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Trubiroha, P. T1 - Quantitative Auswertemöglichkeiten bei der spektralen Bestrahlung – Berechnung des Wirkungsspektrums N2 - Für die Bewertung des Wellenlängeneinflusses auf die Alterungsvorgänge bei der Bestrahlung UV- oder lichtempfindlicher Materialien kann die Methode der spektralen Bestrahlung angewendet werden. Im Prinzip wird dabei das linear dispergierte Spektrum einer Strahlenquelle mit kontinuierlichem Spektrum (z.B. Xe-Lampe) auf eine Probenoberfläche abgebildet, so dass Ort einer Materialänderung und Wellenlänge der Bestrahlung einander zugeordnet werden können. Nachfolgende lokal-auflösende Analysemethoden ermitteln eine Eigenschaftsänderung an einem spezifischen Ort der Probe, aus dem sich dann die Bestrahlungswellenlänge ergibt. Der verwendete Aufbau wird beschrieben. Es wird an einem ausgewählten Beispiel gezeigt, wie durch geeignete Anbindung eines Messsystems zur Bestimmung der spektralen Bestrahlungsstärke und ortsaufgelöste Messungen der Eigenschaftsänderungen eine quantitative Auswertung realisiert werden kann. Der Einfluss nichtlinearer Alterungsverläufe wird diskutiert. Grenzen der Methode werden aufgezeigt und Erweiterungsmöglichkeiten dargestellt. T2 - 46. Jahrestagung der GUS CY - Stutensee-Blankenloch, Germany DA - 22.03.2017 KW - Bewitterung KW - Spektrale Bestrahlung KW - Kunststoffe PY - 2017 SN - 978-3-9816286-9-2 SP - 91 EP - 99 AN - OPUS4-39595 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalbe, Ute A1 - Krüger, Oliver A1 - Berger, Wolfgang A1 - Wachtendorf, Volker A1 - Hally, S. ED - Arm, M. ED - Vandecasteele, C. ED - Heynen, J. ED - Suer, P. ED - Lind, B. T1 - Development of leaching procedures for synthetic turf systems N2 - Scrap tyres are widely reused in the form of granules as infill materials or component of sub-base layers in construction of sporting grounds such as synthetic turf areas and athletic track surfaces. The recycled rubber may contain organic and inorganic pollutants due to the presence of vulcanisation catalysts, stabilisers and other additives which can be released into soil and groundwater in the case of outdoor sports facilities. In order to evaluate the amount of potentially mobile pollutants, leaching tests can be employed. This study aimed particularly at the investigation of the feasibility of column tests using complete synthetic surface flooring or turf system assemblies. The release of zinc and polycyclic aromatic hydrocarbons (PAH) leached from components of sports surfaces containing recycled rubber granules was considered. Additionally, batch tests on coated and uncoated styrene butadiene rubber (SBR) granules aged by artificial weathering were performed to indicate its possible influence on the leaching behaviour of zinc and PAH. The chosen approach of column tests simulating typical complete synthetic sports surface installations has been proven to be feasible and robust. The time-dependent leaching behaviour and interactions between single components can be evaluated by column tests. Zinc was the most relevant contaminant in the eluates and its leachability was enhanced after accelerated ageing by artificial weathering. Leachable PAH were found in relatively low but well detectable amounts which increase by ageing as well. T2 - WASCON 2012 CY - Gothenburg, Sweden DA - 30.05.2012 KW - Waste rubber KW - Artificial turf KW - Leaching behaviour KW - Batch test KW - Column test PY - 2012 SP - 1 EP - 5 PB - ISCOWA and SGI AN - OPUS4-26968 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Falkenhagen, Jana T1 - Combined impact of UV radiation and nitric acid (HNO3) on HDPE jerrycans – comparison of outdoor and lab test N2 - A damaging action of HNO3-55% only occurs in combination with its decomposition into nitrous gases, which can be caused by UV radiation. In a laboratory test, transparent HDPE jerrycans have been exposed to both UV radiation and 55 wt-% nitric acid solution at (41 ± 2)°C, for up to 20 days. For comparison, UV radiant exposure (21 days) and nitric acid exposure (up to 6 weeks) were performed separately, at nearly equal temperatures. The respective damages are compared with FTIR spectroscopy in ATR and HT-gel permeation chromatography (GPC) on a molecular level and with hydraulic internal pressure testing as a component test. For the used jerrycans, relevant oxidation can only be found after the combined exposure. The gradual increase in oxidative damage shows the good reproducibility of the lab exposure. The decomposition of nitric acid into nitrous gases by UV radiation – as well as the jerrycan oxidation – is also observed at lower HNO3 concentration (28 wt- %). Similar results are obtained after outdoor tests. Again, the damage occurs only after combined exposure, in contrast to the exposures to UV only and to HNO3 only, which were conducted in parallel. Outdoor exposures are most readily accepted as they represent possible end-use conditions. However, the reproducibility of these exposures is poor due to the large temporal variations in weather. There are also several safety risks, which is why the number of replicates remains limited. Since the outdoor and lab exposure tests show the same qualitative results, it is appropriate to conduct systematic studies in the laboratory. After 6 days of lab exposure, the oxidation damage is rated as critical, which corresponds to about 1/10 year in Central Europe, according to the UV radiant exposure. It should be noted that this amount can also occur in two sunny weeks. T2 - 24th iapri World Packaging Conference CY - Valencia, Spain DA - 17.06.2024 KW - Ppolyethylene KW - UV exposure KW - Nitric acid KW - Oxidation PY - 2024 VL - 2 SP - 30 EP - 37 PB - ITENE AN - OPUS4-60414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scholz, Philipp A1 - Wachtendorf, Volker A1 - Panne, Ulrich A1 - Weidner, Steffen ED - Scholz, Philipp T1 - Degradation of MDI-based polyether and polyester-polyurethanes in various environments - Effects on molecular mass and crosslinking N2 - Size-exclusion chromatography (SEC) was used to monitor changes of the molecular masses of thermoplastic polyether – and polyester urethane (TPU) exposed to thermal, hydrolytic, and photo-oxidative (UV) Degradation conditions for several days. The thermal treatment was 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. Surprisingly, the influence of oxygen (air) was found to be less distinct. 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 for thermal treatments. The depth of penetration of the UV radiation was estimated 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 esterbased PU in general exhibits a significant higher stability compared to ether-based materials. KW - Polyurethane KW - Thermal degradation KW - UV degradation KW - Molecular masses KW - Crosslinking PY - 2019 UR - https://www.sciencedirect.com/science/article/pii/S0142941819302363 DO - https://doi.org/10.1016/j.polymertesting.2019.04.028 SN - 0142-9418 VL - 77 SP - 105881, 1 EP - 12 PB - Elsevier CY - Amsterdam AN - OPUS4-48619 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scholz, Philipp A1 - Falkenhagen, Jana A1 - Wachtendorf, Volker A1 - Brüll, Robert A1 - Simon, Franz-Georg T1 - Investigation on the Durability of a Polypropylene Geotextile under Artificial Aging Scenarios N2 - Geosynthetics are widely used in various civil engineering applications, such as geotextiles in coastal protection, and display a sustainable alternative to natural mineral materials. However, the full benefits of using geosynthetics can only be gained with a long service lifetime of the products. With the use of added stabilizers to the polymers, service lifetimes can be achieved in the range of 100 years. Therefore, accelerated aging methods are needed for the assessment of the long-term performance of geotextiles. In the present study, the behavior of geosynthetic materials made of polypropylene was investigated under artificial aging conditions involving elevated temperatures ranging from 30 to 80 °C, increased oxygen pressures ranging from 10 to 50 bar in water-filled autoclaves, and UV irradiation under atmospheric conditions. ATR-IR spectroscopy was employed to detect the increase in the carbonyl index over various aging durations, indicating the oxidative degradation of the geotextile. The most pronounced increase was observed in the case of aging through UV irradiation, followed by thermal aging. Elevated pressure, on the other hand, had a lower impact on oxidation. High-temperature size exclusion chromatography was utilized to follow the reduction in molar mass under different degradation conditions, and the results were consistent with those obtained from ATR-IR spectroscopy. In polyolefins such as polypropylene, Hindered Amine Stabilizers (HAS) are used to suppress oxidation caused by UV radiation. The quantitative analysis of HAS was carried out using a UV/Vis method and HPLC. The degradation of UV stabilizers during the aging of geotextiles is responsible for the oxidation and the reduction in the molar mass of polypropylene. From the results, it can be concluded that applications of PP geotextile without soil or sand cover might cause the risk of the formation of microplastic particles. Material selection, design, and maintenance of the construction must follow best practices, including the system’s removal or replacement at end-of-life. Otherwise, a sustainable use of geotextiles in civil engineering is not possible. KW - Geotextiles KW - Microplastic KW - Size exclusion chromatography KW - Accelerated aging PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599739 DO - https://doi.org/10.3390/su16093559 SN - 2071-1050 VL - 16 IS - 9 SP - 1 EP - 15 PB - MDPI AG CY - Basel AN - OPUS4-59973 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Falkenhagen, Jana T1 - Combined impact of UV radiation and nitric acid on high‐density polyethylene containers as a laboratory test N2 - In a laboratory test, transparent high‐density polyethylene (HDPE) jerrycans have been exposed to both UV radiation and 55 wt‐% nitric acid solution at (41 ± 2)°C, for up to 20 days. For comparison, UV radiant exposure (21 days) and nitric acid exposure (up to 6 weeks) were performed separately, at nearly equal temperatures. The damages are compared with FTIR spectroscopy in ATR and HT‐gel permeation chromatography(GPC) on a molecular level and with hydraulic internal pressure testing as a component test. For the used jerrycans, relevant oxidation can only be found after the combined exposure. This is caused by the decomposition of nitric acid into nitrous gases by UV radiation, which is also observed at lower concentrations (28 wt‐%). After 6 days of laboratory exposure, this is rated as critical, which corresponds to about 1/10 year in Central Europe, according to the UV radiant exposure. The gradual increase in oxidative damage shows the reproducibility of the test. KW - Molecular mass distribution KW - High-density polyethylene KW - Nitric acid KW - UV radiation PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550141 DO - https://doi.org/10.1002/pts.2673 SN - 0894-3214 VL - 35 IS - 10 SP - 729 EP - 735 PB - Wiley CY - New York, NY AN - OPUS4-55014 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wachtendorf, Volker T1 - Einfluss von Feuchte und Nässe auf die Witterungs-induzierte Alterung am Beispiel eines Polyurethans N2 - Bei der Bewitterung von Polymeren kommt es auf molekularer Ebene zur Alterung, die sich in verschiedenen Eigenschaften als unterschiedlich starke Änderung äußert. Art und Geschwindigkeit dieser molekularen Alterung und die damit einhergehenden Eigenschaftsänderungen hängen dabei neben einer Reihe anderer Einflussfaktoren von der Art und Intensität der Beanspruchung ab. In diesem Beitrag soll der relative Einfluss des Wassers als Feuchte und Nässe unter den Beanspruchungsfaktoren untersucht werden. Die Unterscheidung von Luftfeuchte und Nässe bezüglich ihrer Wirkung ist dabei notwendig, weil die stehende Nässe zusätzliche Extraktionswirkung besitzt und auch die verfügbare Sauerstoffmenge beeinflusst. Dazu wurde ein Polymer, das im Rahmen des BAM-internen Projektes PolyComp untersucht wird, künstlich bewittert. Hierzu wurde ein Fluoreszenzlampengerät mit UV-A 340 nm Leuchtstoffröhren verwendet, in dessen Probenraum durch zusätzliche Kammern die gleichzeitige Bewitterung unter drei unterschiedlichen Feuchte-Varianten realisiert wurde (bei konstanter Temperatur): - UV und trocken - UV und hohe Luftfeuchte - UV und stehende Nässe. Das gleichzeitige Einwirken der einzelnen Einflussfaktoren kann dabei konkurrierende oder aufeinander folgende chemische Reaktionen und physikalische Prozesse und somit ein anderes Ergebnis bewirken, als wenn sie isoliert nacheinander auf eine Probe eingewirkt hätten. Über die erwähnten Varianten hinaus kann auch noch der spezifische Einfluss der UV-Strahlung mit untersucht werden, weil die Proben im Bereich ihrer Befestigung verdeckt sind. Die Methodik und erste Ergebnisse dieser Untersuchung werden präsentiert. T2 - 46. Jahrestagung der Gesellschaft für Umweltsimulation (GUS) 2017 CY - Stutensee-Blankenloch bei Karlsruhe, Germany DA - 22.03.2017 KW - Polyurethan KW - TPU KW - Bewitterung KW - Feuchte KW - Nässe KW - UV PY - 2017 AN - OPUS4-39905 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wachtendorf, Volker A1 - Geburtig, Anja A1 - Elert, Anna Maria A1 - Weidner, Steffen T1 - Einfluss von Feuchte und Nässe auf die Witterungs-induzierte Alterung am Beispiel eines Polyurethans N2 - In diesem Beitrag soll der relative Einfluss des Wassers als Feuchte und Nässe unter den Beanspruchungsfaktoren untersucht werden. Die Unterscheidung von Luftfeuchte und Nässe bezüglich ihrer Wirkung ist dabei notwendig, weil die stehende Nässe zusätzliche Extraktionswirkung besitzt und auch die verfügbare Sauerstoffmenge beeinflusst. Dazu wurde ein Polymer, das im Rahmen des BAM-internen Projektes PolyComp untersucht wird, künstlich bewittert. Hierzu wurde ein Fluoreszenzlampengerät mit UV-A 340 nm Leuchtstoffröhren verwendet, in dessen Probenraum durch zusätzliche Kammern die gleichzeitige Bewitterung unter drei unterschiedlichen Feuchte-Varianten realisiert wurde (bei konstanter Temperatur): - UV und trocken - UV und hohe Luftfeuchte - UV und stehende Nässe Das gleichzeitige Einwirken der einzelnen Einflussfaktoren kann dabei konkurrierende oder aufeinander folgende chemische Reaktionen und physikalische Prozesse und somit ein anderes Ergebnis bewirken, als wenn sie isoliert nacheinander auf eine Probe eingewirkt hätten. Über die erwähnten Varianten hinaus kann auch noch der spezifische Einfluss der UV-Strahlung mit untersucht werden, weil die Proben im Bereich ihrer Befestigung verdeckt sind. Die Methodik und erste Ergebnisse dieser Untersuchung werden präsentiert. T2 - 46. Jahrestagung der Gesellschaft für Umweltsimulation (GUS) 2017 CY - Stutensee-Blankenloch bei Karlsruhe, Germany DA - 22.03.2017 KW - Polyurethan KW - TPU KW - Bewitterung KW - UV KW - Feuchte KW - Nässe PY - 2017 SN - 978-3-9816286-9-2 VL - 46 SP - 251 EP - 261 PB - Gesellschaft für Umweltsimulation e. V CY - Pfinztal (Berghausen) AN - OPUS4-39906 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Theiler, Geraldine A1 - Wachtendorf, Volker A1 - Elert, Anna Maria A1 - Weidner, Steffen T1 - Effects of UV radiation on the friction behavior of thermoplastic polyurethanes N2 - The effects of weathering exposure on unfilled and filled thermoplastic polyurethanes (TPU) materials are described as performed under different humidity conditions. For this purpose, a weathering device was used with UV-A 340 nm lamps at a constant temperature of 40 °C. The effects of environmental (UV and humidity condition) degradation on the frictional properties of TPU materials are presented along with surface analyses to characterize the chemistry of the degradative process. Photooxidative degradation of unfilled polymer leads to deterioration of physical and mechanical properties, which affects its tribological behavior significantly. Due to crosslinking, the stiffness of the material increases, reducing drastically the friction coefficient of unfilled TPUs. The frictional behavior of glass fiber reinforced TPU is less affected by radiation. KW - Photooxidation KW - UV radiation KW - Friction KW - TPU KW - Humidity PY - 2018 DO - https://doi.org/10.1016/j.polymertesting.2018.08.006 SN - 0142-9418 SN - 1873-2348 VL - 70 SP - 467 EP - 473 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-45709 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scholz, Philipp A1 - Wachtendorf, Volker A1 - Elert, Anna Maria A1 - Falkenhagen, Jana A1 - Becker, Roland A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Tschiche, Harald A1 - Reinsch, Stefan A1 - Weidner, Steffen ED - Scholz, Philipp T1 - Analytical toolset to characterize polyurethanes after exposure to artificial weathering under systematically varied moisture conditions N2 - Polyether and -ester urethanes (PU) were exposed to artificial weathering at 40 °C and artificial UV radiation in a weathering chamber. In 3 parallel exposures, humidity was varied between dry, humid, and wet conditions. Material alteration was investigated by various analytical techniques like size exclusion chromatography (SEC), liquid chromatography-infrared spectroscopy (LC-FTIR), thermal-desorption gas chromatography-mass spectrometry (TD-GC-MS), fluorescence mapping and dynamic mechanical analysis (DMA). Our results show that depending on the weathering conditions, different degradation effects can be observed. By means of SEC an initial strong decrease of the molar masses and a broadening of the mass distributions was found. After a material dependent time span this was followed by a plateau where molar mass changes were less significant. A minor moisture-dependent degradation effect was only found for polyester PU. Fluorescence measurements on two materials revealed an increase in the luminescence intensity upon weathering process reaching a saturation level after about 500 h. The changes in the optical properties observed after different exposure conditions and times were very similar. The TD-GC-MS data showed the fate of the stabilizers and antioxidant in the course of weathering. LC-FTIR measurements revealed a change in peak intensities and the ratio of urethane and carbonyl bands. KW - Polyurethane KW - Artificial weathering KW - Moisture KW - Crosslinking KW - Degradation PY - 2019 UR - https://www.sciencedirect.com/science/article/pii/S0142941819303708 DO - https://doi.org/10.1016/j.polymertesting.2019.105996 SN - 0142-9418 VL - 78 SP - 105996, 1 EP - 9 PB - Elsevier CY - Amsterdam AN - OPUS4-48625 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -