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 - CONF A1 - Geburtig, Anja A1 - Goedecke, Thomas A1 - Wachtendorf, Volker ED - Reichert, T. T1 - A new irradiation device for medium scale plastic products N2 - A new irradiation device for the exposure of plastic products is presented. Developed in the BAM division 3.1 "Dangerous Goods Packaging" it can be used for artificial UV irradiation of plastic Containers filled with hazardous liquids. Present regulations and tests only investigate the exposure effects of UV and of media separately, but as the damaging effect is expected to be synergistic for at least some media, a combined test was looked for. A chamber of 60 cm by 60 cm base area and 1 m height gives space for up to 40 cm wide objects. Two fluorescent UV lamp arrays are arranged on opposite walls, separated from the chamber by quartz glass panes. By continuously rotating the exposure object by means of a rotary disc that the object is placed on, spatial irradiation homogeneity is achieved over the exposure duration. The spectral irradiance of the chosen UVA 340 nm lamps gives the best match of global solar radiation in the short wavelength ränge. The close arrangement of the UVA lamps (15 each side) results in 60 W m'2 UV irradiance. Constant temperature is adjusted to typically 40 °C by the control of the fan speed. This temperature is chosen, as it is the required temperature for three week storage of filled polyethylene Containers, for proving Chemical compatibility in the field of dangerous goods. To ensure homogeneity, an interiorfan provides for air circulation. T2 - 7th European weathering symposium - Natural and artificial ageing of polymers CY - Naples, Italy DA - 16.09.2015 KW - Weathering KW - UV irradiation PY - 2015 SN - 978-3-9816286-6-1 N1 - Serientitel: CEEES Publication – Series title: CEEES Publication IS - 17 SP - 91 EP - 96 AN - OPUS4-34353 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Frasca, Daniele A1 - Schulze, Dietmar A1 - Wachtendorf, Volker A1 - Huth, Christian A1 - Schartel, Bernhard T1 - Multifunctional multilayer graphene/elastomer nanocomposites N2 - Elastomers are usually reinforced and employed in different applications. Various different nanoparticles, including layered silicates, carbon nanotubes, and expanded graphite, are currently being used as nanofiller. Multilayer Graphene (MLG) is proposed as promising nanofiller to improve the functional properties of Chlorine-Isobutylene-Isoprene Rubber (CIIR), Nitrile-Butadiene Rubber (NBR), Natural Rubber (NR) and Styrene–Butadiene Rubber (SBR) at low concentrations. MLG is constituted by only approximately 10 graphene sheets. Nanocomposites with extremely low MLG content (3 phr) showed evident improvement in rheological, mechanical and curing properties. The Young's modulus of the nanocomposites increased more than twice in comparison with the unfilled rubbers. MLG also improved the weathering resistance of the different rubbers. The nanocomposites conserved their initial mechanical properties against weathering exposure. KW - Elastomer KW - Nanocomposite KW - Multilayer graphene PY - 2015 DO - https://doi.org/10.1016/j.eurpolymj.2015.07.050 SN - 0014-3057 SN - 1873-1945 VL - 71 SP - 99 EP - 113 PB - Elsevier Ltd. CY - Oxford AN - OPUS4-33843 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tan, Yi A1 - Wachtendorf, Volker A1 - Kukofka, Tobias A1 - Klack, Patrick A1 - Ruder, J. A1 - Lin, Xuebao A1 - Schartel, Bernhard T1 - Degradation of flame retardance: A comparison of ethylene‐vinyl acetate and low‐density polyethylene cables with two different metal hydroxides N2 - The durability of flame retardancy is a challenge for cables over long lifetimes. The degradation of flame retardance is investigated in two kinds of exposures, artificial weathering and humidity. In this basic study, typical mineral flame retardants in two polymers frequently used in cable jackets are investigated to get the fundamental picture. Aluminum hydroxide (ATH) and magnesium hydroxide (MDH) are compared in ethylene‐vinyl acetate (EVA), and further in EVA and linear low‐density polyethylene (LLDPE) cables containing the same ATH. The changes in chemical structure at the surface are studied through attenuated total reflectance Fourier transform infrared spectroscopy (ATR‐FTIR), the formation of cracks, and changes in color are investigated. The cone calorimeter and a bench scale fire testing cable module are utilized to evaluate the fire behavior of the cables. Although the flame retardancy deteriorated slightly, it survived harsh exposure conditions for 2000 h. Compared to EVA/MDH and LLDPE/ATH, the fire behavior of EVA/ATH is the least sensitive. Taken together, all of the results converge to estimate that there will be no problem with flame retardancy performance, for materials subjected to natural exposure for several years; the durability of fire retardancy is questionable for longer periods, and thus requires further investigation. KW - Durability KW - Flame retardant KW - Aluminum hydroxide (ATH) KW - Magnesium hydroxide KW - Ethylene-vinyl acetate KW - Cables KW - Weathering PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-519573 DO - https://doi.org/10.1002/app.50149 VL - 138 IS - 14 SP - 50149 PB - Wiley AN - OPUS4-51957 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Daus, Lars-Hendrik A1 - Schartel, Bernhard A1 - Wachtendorf, Volker A1 - Mangelsdorf, R. A1 - Korzen, Manfred T1 - A chain is no stronger than its weakest link: Weathering resistance of water-based intumescent coatings for steel applications N2 - A systematic approach was used to investigate the weathering-induced degradation of a common water–based intumescent coating. In this study, the coatings are intended for humid indoor applications on steel substrates. The coating contains ammonium polyphosphate, pentaerythritol, melamine, and polyvinyl acetate. By replacing each ingredient with a less water-soluble substance, the most vulnerable substances, polyvinyl acetate and pentaerythritol, were identified. Furthermore, the weathering resistance of the system was improved by exchanging the ingredients. The coatings were stressed by artificial weathering tests and evaluated by fire tests. Thermogravimetry and Fourier-transform infrared spectroscopy were used to study the thermal decomposition. This study lays the foundation for the development of a new generation of water-based intumescent coatings. KW - Intumescence KW - Fire resistance KW - Fire protective coatings KW - Weathering KW - Thermogravimetric analyses PY - 2021 DO - https://doi.org/10.1177/0734904120961064 SN - 0734-9041 SN - 1530-8049 VL - 39 IS - 1 SP - 72 EP - 102 PB - SAGE AN - OPUS4-52015 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wachtendorf, Volker A1 - Schartel, Bernhard A1 - Lin, Xuebao A1 - Tan, Yi A1 - Schoch, R. A1 - Lang, M. A1 - Tröppner, O. A1 - Bosse, M. ED - Ziegahn, K.-F. T1 - Untersuchung der Witterungsbeständigkeit komplexer Funktionalitäten von Polymerwerkstoffen durch künstliche Bewitterung: Flammschutz N2 - In den letzten Jahrzehnten wurde die Degradation der polymeren Matrix von flammgeschützten Polymeren eingehend untersucht. Erst in den letzten Jahren jedoch hat sich die Frage der Lebensdauer der Funktionalität des Flammschutzes selbst als wichtige Fragestellung herauskristallisiert, z.B. bei Kabeln. Deshalb sollte diese Fragestellung durch systematisch-variierte künstliche Klima- und Bewitterungstests an flammgeschützten Polymerwerkstoffen untersucht werden. T2 - 50. Jahrestagung der Gesellschaft für Umweltsimulation (GUS) CY - Online meeting DA - 23.03.2022 KW - Flammschutz, Witterungsbeständigkeit, Langzeitbeständigkeit, UV, E&E PY - 2022 SN - 978-3-9818507-7-2 VL - 50 SP - 143 EP - 148 CY - Pfinztal (Berghausen) AN - OPUS4-54543 LA - deu 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 - 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 - JOUR A1 - Qiu, Y. A1 - Wachtendorf, Volker A1 - Klack, Patrick A1 - Qian, L. A1 - Liu, Z. A1 - Schartel, Bernhard T1 - Improved flame retardancy by synergy between cyclotetrasiloxane and phosphaphenanthrene/triazine compounds in epoxy thermoset N2 - A siloxane compound (MVC) and a bi-group phosphaphenanthrene/triazine compound (TGD) were employed in epoxy thermosets to explore high-efficiency flame retardant systems. With only 1wt% MVC and 3wt% TGD, an epoxy thermoset passed UL 94 V-0 rating test and achieved a limiting oxygen index value of 34.0%, exhibiting an excellent flame retardant effect. The MVC/TGD system not only decreased the peak value of heat release rate and effective heat of combustion but also imparted an improved charring ability to thermosets, thereby outstandingly reducing the flammability of 1%MVC/3%TGD/EP. Compared with the fire performance of 4%TGD/EP and 4%MVC/EP, the MVC/TGD system showed an obvious flame retardant synergistic effect, mainly depending on the general improvement of flame inhibition, charring and barrier effects of the thermoset during combustion. Evolved gas analysis combinedwith condensed-phase pyrolysis product Analysis jointly revealed the details of the changed pyrolysis mode. KW - Flame retardant KW - Epoxy resin KW - Synergy KW - Siloxane KW - DOPO KW - Triazine PY - 2017 DO - https://doi.org/10.1002/pi.5466 SN - 0959-8103 SN - 1097-0126 VL - 66 IS - 12 SP - 1883 EP - 1890 PB - Wiley AN - OPUS4-42950 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Trubiroha, P. T1 - Evaluation of outdoor exposures by means of exposure response functions N2 - Outdoor exposure tests are a common tool to evaluate the weathering resistance of a polymeric material or component. However, they have only a limited validity, mainly due to the limited reproducibility of the weather as well as of the bad adaptability to other exposure sites. Typically, an outdoor exposure is characterized by the measured radiant exposure; sometimes averaged temperature data are added. These can be – separately – related to long-term annual means, to get an idea on the severity of the exposure. However, as for polymeric ageing, irradiance and temperature act simultaneously, such severity of an outdoor exposure could be better described by a computed property change of a similar material, which is calculated from the hourly irradiance and temperature values on the base of established exposure response functions. In this way, various outdoor exposures are evaluated. For several exposure sites, annual deviations of the ageing amount are related to annual mean values, to evaluate the weathering reproducibility at the exposure site. Additionally, correlations to relevant weather parameters are illuminated. Also some specific exposure conditions, such as tilt angle, are tested. Compared to the use of weathering reference materials, this procedure unfavourably depends on the availability of a suited control as well as on the quality of the established exposure response function. In contrast, it enables a later exposure evaluation, on the base of documented weather data, if for instance no reference material was exposed. T2 - 8th European Weathering Symposium CY - Vienna, Austria DA - 20.09.2017 KW - Weathering KW - Service life prediction KW - Photodegradation PY - 2017 SN - 978-3-9818507-1-0 VL - 18 SP - 127 EP - 135 PB - Thomas Würtz Grafik Design CY - Karlsruhe AN - OPUS4-42126 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -