TY - JOUR A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Trubiroha, P. T1 - Exposure response function for a quantitative prediction of weathering caused aging of polyethylene JF - Materials Testing N2 - The exposure response function of the carbonyl formation over the bulk has been determined for a high-density polyethylene of a thickness of 200 μm, which was used as a weathering reference material according to ISO TR 19032. To this end, spectral sensitivity was studied by local measurement of the effect of spectrally dispersed irradiation. Both the exposure device and the methodology of determination are described. The temperature dependency of photooxidation was determined by UV exposure at various temperatures between 23 and 80 °C. Deviations from linearity and thus reciprocity below 40 °C are discussed and assumed to be related to diffusion limitations. An Arrhenius approach –based on data of linear carbonyl formation – has been incorporated into the exposure response function. Using this exposure response function, aging in terms of the distribution of a quantitative property change over a plastic component can be predicted for a specific outdoor location with real chronologic weather data as input for the exposure. Thus, artificial and natural weathering can be linked and compared. The established exposure response function has been validated by outdoor exposure results from the literature. If an estimated diffusion limitation is taken into consideration, calculations and published data are in good agreement. KW - Irradiation KW - Weathering KW - Spectral sensitivity KW - Temperature dependency KW - Spectral irradiation PY - 2019 DO - https://doi.org/10.3139/120.111348 SN - 0025-5300 VL - 61 IS - 6 SP - 517 EP - 526 PB - Carl Hanser Verlag GmbH & Co. KG AN - OPUS4-48295 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Krüger, Simone A1 - Wachtendorf, Volker A1 - Hennecke, Manfred T1 - Excitation energy transfer of a bichromophoric cross-shaped molecule investigated by polarized fluorescence spectroscopy JF - The journal of chemical physics N2 - The excitation energy transfer (EET) of a bichromophoric cross-shaped molecule was investigated by stationary polarized fluorescence spectroscopy in the solid state. For this purpose 2,2[prime],7,7[prime]-tetrakis(biphenyl-4-yl)-9,9[prime]-spirobifluorene was embedded in a polymeric bisphenol-A-polycarbonate (PC) matrix. The dependence of the fluorescence on concentration and wavelength was determined. The role of the intermolecular and intramolecular EET is dealt with separately and discussed by means of the degree of polarization. The intermolecular excitation energy transfer is described in terms of a Förster transfer mechanism. The intramolecular transfer is prevented for the zero-point vibrational levels by the molecular cross-shaped structure, but is found for a wide range of wavelength, presumably based on vibrationally excited states. PY - 2000 DO - https://doi.org/10.1063/1.481620 SN - 0021-9606 SN - 1089-7690 VL - 112 IS - 22 SP - 9822 EP - 9827 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-1038 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Erdmann, Maren A1 - Niebergall, Ute A1 - Wachtendorf, Volker A1 - Böhning, Martin T1 - Evaluation of UV-induced embrittlement of PE-HD by Charpy impact test JF - Journal of Applied Polymer Science N2 - The impact fracture behavior of two common high-density polyethylene grades for container applications were intensively studied by the instrumented Charpy impact test after well-defined exposure to UV-irradiation. Individual stages of the impact event, such as crack initiation and crack propagation energy as well as maximum impact load, were investigated from the recorded load–deflection curves. UV-induced material property changes were further investigated by infrared spectroscopy, differential scanning calorimetry, and dynamic-mechanical analysis as well as density measurements. Based on the results of the Charpy impact test, three indicators were identified to describe the extend of photooxidation on high-density polyethylene: (a) a reduced Charpy impact strength—at least to half of its initial value for a distinctly brittle impact fracture, (b) a marked decrease in the crack propagation contribution to the impact strength, and (c) an increase of the brittle features of the fracture surface. KW - Degradation KW - Mechanical properties KW - Packaging KW - Polyolefins KW - Polyethylene PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509130 DO - https://doi.org/10.1002/APP.49069 SN - 0021-8995 VL - 137 IS - 36 SP - 49069 PB - Wiley AN - OPUS4-50913 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tang, S. A1 - Wachtendorf, Volker A1 - Klack, Patrick A1 - Qian, Lijun A1 - Dong, Y. A1 - Schartel, Bernhard T1 - Enhanced flame-retardant effect of montmorillonite/phosphaphenanthrene compound in an epoxy thermoset JF - RSC Advances N2 - A phosphaphenanthrene and triazinetrione group containing flame retardant (TAD) is combined with organically modified montmorillonite (OMMT) in epoxy resin thermosets (EP) to improve the performance of the flame-retardant system. When only 1 wt% OMMT/4 wt% TAD is introduced into the EP, the limited oxygen index (LOI) rises from 26% to 36.9% and a V-0 rating is achieved in a UL 94 test. The decomposition and pyrolysis products in the gas phase and condensed phase were characterized using thermogravimetry-Fourier transform infrared spectroscopy (TG-FTIR). The influence on the decomposition of EP, such as the increase in char yield, is limited with the incorporation of OMMT; a large amount of the phosphorus is released into the gas phase. The flame-retardant effect evaluation based on cone calorimeter data testified that OMMT improves the protective-barrier effect of the fire residue of OMMT/TAD/EP on the macroscopic scale, while TAD mainly causes flame inhibition. The fire residues showed a corresponding macroscopic appearance (digital photo) and microstructure (scanning electron microscope [SEM] results). The protective barrier effect of OMMT and the flame-inhibition effect of TAD combined to exert a superior flame-retardant effect, resulting in sufficient flame-retardant performance of OMMT/TAD/EP KW - Flame retardant KW - Nanocomposite KW - DOPO KW - Thermoset KW - Epoxy resin KW - TG-FTIR PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-388865 DO - https://doi.org/10.1039/c6ra25070j SN - 2046-2069 VL - 7 IS - 2 SP - 720 EP - 728 AN - OPUS4-38886 LA - eng 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 JF - Polymers Testing 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 - Tan, Yi A1 - Wachtendorf, Volker A1 - Klack, Patrick A1 - Kukofka, Tobias A1 - Ruder, J. A1 - Schartel, Bernhard T1 - Durability of the flame retardance of ethylene-vinyl acetate copolymer cables: Comparing different flame retardants exposed to different weathering conditions JF - Journal of Applied Polymer Science N2 - Scientific publications addressing the durability of the flame retardance of cables during their long-term application are rare and our understanding lacks. Three commercial flame retardants, aluminum hydroxide, aluminum diethyl phosphinate (AlPi-Et), and intumescent flame retardant based on ammonium polyphosphate, applied in ethylene-vinyl acetate copolymer (EVA) model cables, are investigated. Different artificial aging scenarios were applied: accelerated weathering (UV-irradiation/temperature/rain phases), humidity exposure (elevated temperature/humidity), and salt spray exposure. The deterioration of cables’ surface and flame retardancy were monitored through imaging, color measurements, attenuated total reflectance Fourier transform infrared spectroscopy, and cone calorimeter investigations. Significant degradation of the materials’ surface occurred. The flame retardant EVA cables are most sensitive to humidity exposure; the cable with AlPi-Et is the most sensitive to the artificial aging scenarios. Nevertheless, substantial flame retardance persisted after being subjected for 2000 h, which indicates that the equivalent influence of natural exposure is limited for several years, but less so for long-term use. KW - Durability KW - Flame retardant KW - Cable KW - Weathering KW - Cone calorimeter PY - 2020 DO - https://doi.org/10.1002/APP.47548 SN - 0021-8995 VL - 137 IS - 1 SP - 47548 PB - Wiley AN - OPUS4-50237 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kömmling, Anja A1 - Chatzigiannakis, E. A1 - Beckmann, Jörg A1 - Wachtendorf, Volker A1 - von der Ehe, Kerstin A1 - Braun, Ulrike A1 - Jaunich, Matthias A1 - Schade, U. A1 - Wolff, Dietmar T1 - Discoloration Effects of High-Dose gamma-Irradiation and Long-Term Thermal Aging of (U) HMW-PE JF - International Journal of Polymer Science N2 - Two polyethylene types with ultra-high (UHMWPE) and high molecular weight (HMW-PE) used as neutron radiation shielding materials in casks for radioactive waste were irradiated with doses up to 600 kGy using a 60Co gammasource. Subsequently, thermal aging at 125∘C was applied for up to one year. Degradation effects in the materials were characterized using colorimetry, UV-Visspectroscopy, IR spectroscopy, and DSC. Both materials exhibited a yellowing upon irradiation.The discoloration of UHMW-PE disappeared again after thermal aging.Therefore, the yellowing is assumed to originate fromannealable color centers in the formof free radicals that are trapped in the crystalline regions of the polymer and recombine at elevated temperatures. For the antioxidantcontaining HMWPE, yellowing was observed after both irradiation and thermal aging. The color change was correlated mainly to decomposition products of the antioxidant in addition to trapped radicals as in UHMW-PE. Additionally, black spots appeared after thermal aging of HMW-PE. KW - Irradiation KW - UHMWPE KW - Colour center KW - Yellowness index PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-423992 DO - https://doi.org/10.1155/2017/1362491 SN - 1687-9422 VL - 2017 IS - Article ID 1362491 SP - 1 EP - 10 PB - Hindawi AN - OPUS4-42399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kalbe, Ute A1 - Krüger, Oliver A1 - Wachtendorf, Volker A1 - Berger, Wolfgang A1 - Hally, S. T1 - Development of leaching procedures for synthetic turf systems containing scrap tyre granules JF - Waste and biomass valorization 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. KW - Waste rubber KW - SBR KW - Artificial turf KW - Leaching KW - behaviour KW - Column test KW - Batch test KW - Weathering PY - 2013 DO - https://doi.org/10.1007/s12649-013-9248-5 SN - 1877-2641 SN - 1877-265X VL - 4 IS - 4 SP - 745 EP - 757 PB - Springer Science + Business Media CY - Dordrecht AN - OPUS4-29454 LA - eng 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 JF - Polymer degradation and stability 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 - 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 JF - Polymer Testing 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 - 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 JF - Journal of Applied Polymer Science 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 - Bandow, Nicole A1 - Will, Verena A1 - Wachtendorf, Volker A1 - Simon, Franz-Georg T1 - Contaminant release from aged microplastic JF - Environmental Chemistry N2 - Recycled plastic granules of high-density polyethylene, polyvinyl chloride and polystyrene the size of microplastics were exposed to artificial aging conditions (2000 h; photooxidative and thermo-oxidative) to simulate their fate outdoors. Their potential to leach into water during the aging process was investigated using column percolation tests. Aging-related changes on the surface of the material were characterised by IR measurements indicating oxidation reactions with the formation of new adsorption bands (C=O, C–O and OH), especially in the case of photooxidative aging. These findings were confirmed by the identification of leachable organic compounds. Leaching of total organic carbon, Cl, Ca, Cu and Zn is clearly affected by changes due to aging, and their release is increased after photooxidative aging. In general, exposure to photooxidative conditions shows a greater influence on aging and thus on leaching and seems to be the more important mechanism for the aging of microplastic in the environment. Comparison with the total content of inorganic species revealed that, for most elements, less than 3% of the total content is released after 2000 h of photooxidative aging. KW - Column percolation tests KW - Heavy metals KW - Photo-oxidation KW - Thermo-oxidation PY - 2017 DO - https://doi.org/10.1071/EN17064 SN - 1448-2517 SN - 1449-8979 VL - 14 IS - 6 SP - 394 EP - 405 AN - OPUS4-43222 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 JF - Packaging Technology and Science 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 SP - 1 EP - 7 PB - John Wiley & Sons Ltd AN - OPUS4-55014 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Schmidt, Anita A1 - Goedecke, Thomas T1 - Combined impact of UV radiation and nitric acid on HDPE containers during outdoor exposure T1 - Kombinierte Einwirkung von UV-Strahlung und Salpetersäure auf HDPE-Behälter bei der Freibewitterung JF - Materials Testing N2 - Unpigmented HDPE jerrycans filled with nitric acid (55%) and water respectively had been exposed to outdoor conditions for one Berlin summer season. As both liquids underwent equal temperature progression, exposure effects of UV radiation and nitric acid as well as of their combination can be separated and compared. On the basis of various property changes after these exposures, synergistic action is evaluated and compared to a damaged Intermediate Bulk Container (IBC) from a transport accident. It is found that carbonyl formation goes along with lightness increase in color measurement due to microcracking and with a worsening in mechanical behavior, all of them showing synergistic effects of UV and nitric acid exposure. In contrast, embedding nitrogen compounds goes along with yellowing of the material but cannot be correlated to oxidation. The reason for intensified damaging is the decomposition of the 55-percent nitric acid and formation of nitrogen oxides even at ambient temperatures, caused by UV radiation. Thus, damaging effects become similar to those caused by fuming nitric acid exposure at temperatures above 60 °C, with the result of strong oxidative degradation of the polyethylene. In contrast, exclusive exposure to the 55-percent nitric acid at 40 °C does not cause any failure. It can therefore be assumed that also the damaged IBC had been exposed to both UV radiation and nitric acid, probably outdoors. KW - Polyethylene KW - Nitric acid KW - UV radiation KW - Outdoor weathering KW - Resistance PY - 2018 DO - https://doi.org/10.3139/120.111148 SN - 0025-5300 VL - 60 IS - 3 SP - 257 EP - 264 PB - Carl Hanser Verlag CY - München AN - OPUS4-44567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Geburtig, Anja A1 - Goedecke, Thomas A1 - Wachtendorf, Volker T1 - Combined impact of ultraviolet and chemical fluids on high-density polyethylene packaging material JF - Packaging technology & science N2 - To investigate the ageing behaviour of filled plastic containers outdoors, square cuts of the wall of two high-density polyethylene (HDPE) types were exposed to ultraviolet (UV) radiation at their front side and to specific liquid chemicals (de-ionized water, surfactant or White Spirit) at their back. The UV radiant exposure at the front side was 80 MJ/m². To compare the actions of the different exposures, separate dark backside fluid exposures were performed, in parallel. Besides, UV weathering was carried out until a UV radiant exposure of 325 MJ/m², being roughly comparable to outdoor exposure of one year in Northern Australia. An unpigmented HDPE included in the investigation gave no sufficient protection for the White Spirit. In addition, it showed clear degradation after several of these exposures. In combination with the White Spirit, an increase of carbonyl bonds was measured, presumably assignable to degradation products of the White Spirit. For a pigmented HDPE material, with the implemented combined exposures, no relevant damage was observed, within applied the exposure period. KW - Weathering KW - UV KW - HDPE KW - Packaging PY - 2012 DO - https://doi.org/10.1002/pts.959 SN - 0894-3214 VL - 25 IS - 1 SP - 53 EP - 61 PB - Wiley CY - Chichester, UK AN - OPUS4-25417 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Appajaiah, Anilkumar A1 - Wachtendorf, Volker A1 - Daum, Werner T1 - Climatic exposure of polymer optical fibers: Thermooxidative stability characterization by chemiluminescence JF - Journal of applied polymer science N2 - The optical transmission stability was investigated for commercially available polymer optical fibers (POFs) which were exposed to a climate of 92°C and 95% relative humidity for about 3300 h. The optical transmission stability of POFs was correlated to their thermooxidative stability. POFs possessed identical core material, poly(methyl methacrylate), but they differed in the materials used for the claddings. The optical transmission was measured online using a prototype device called multiplexer. The chemiluminescence (CL) technique was applied to characterize the thermooxidative stability and degradation of POFs. CL analysis reveals the thermooxidative degradation of bare POFs (core and cladding), predominantly of the claddings, as a result of climatic exposure. Ultraviolet-visible transmittance measurements demonstrated more changes in the claddings as compared to the cores due to degradation. The CL and optical measurements data indicated that the optical transmission stability of POFs was dependent mainly on the thermooxidative stability of the claddings and their chemical compositions. KW - Ageing KW - Polymer optical fiber KW - Degradation KW - Chemiluminescence KW - Transparency PY - 2007 DO - https://doi.org/10.1002/app.23955 SN - 0021-8995 SN - 1097-4628 VL - 103 IS - 3 SP - 1593 EP - 1601 PB - Wiley InterScience CY - Hoboken, NJ AN - OPUS4-19072 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Krüger, Simone A1 - Wachtendorf, Volker A1 - Hennecke, Manfred T1 - Chemiluminescence: A promising new testing method for plastic optical fibers JF - Journal of lightwave technology N2 - The thermo-oxidative degradation of a polymeric optical cable is investigated by chemiluminescence, The results are reliable and reproducible. Two distinct processes are reported marked by a peak and a plateau behavior versus the time, respectively. Both processes are ruled by thermally activated processes. Beside the dependencies of temperature and time, the influence of absorbed water is discussed. Chemiluminescence is proposed as a promising candidate for a suitable testing method assessing the thermo-oxidative stability of plastic optical fibers and cables. it requires not more than a simple one-day testing procedure and has the advantage that it can be carried out even within the lo cv temperature ranges of the cables' intended use. KW - Chemiluminescence KW - Chemilumineszenz PY - 1999 DO - https://doi.org/10.1109/50.803022 SN - 0733-8724 SN - 1558-2213 VL - 17 IS - 11 SP - 2291 EP - 2296 PB - Institute of Electrical and Electronics Engineers CY - New York, NY AN - OPUS4-718 LA - eng 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 JF - JCT coatingsTech 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 - JOUR A1 - Wachtendorf, Volker A1 - Geburtig, Anja T1 - Chemiluminescence for the early detection of weathering effects of coatings - Part I: Fundamentals JF - JCT coatingsTech 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 - JOUR A1 - Appajaiah, Anilkumar A1 - Wachtendorf, Volker A1 - Daum, Werner T1 - Characterization of thermo-oxidative stability of polymer optical fibers using chemiluminescence technique JF - Polymer degradation and stability N2 - The thermo-oxidative stability of commercially available polymer optical fibers (POFs) and their components (cores and claddings) was investigated. All the bare POFs (core and cladding only) studied here were based on poly(methyl methacrylate) (PMMA) core. The fibers were exposed to 100 °C/low humidity for about 4200 h. Chemiluminescence (CL) technique was applied to investigate the thermo-oxidative stability and for measuring the transmission loss during exposure a prototype device called multiplexer was used. POFs exhibited variation in thermo-oxidative stability although they possessed identical core material PMMA. This was due to difference in the chemical compositions of claddings. Claddings were more susceptible to the thermo-oxidative degradation compared to cores. The thermo-oxidative degradation of both the cladding and the core was found in POFs as a result of climatic exposure. POFs showed an early drop-off followed by a slow decline of transmission. The early drop-off of transmission was attributed to physical changes like thermal expansion and the slow decline of transmission to chemical changes like oxidative degradation of POFs. A good linear relationship between optical transmission stability and thermo-oxidative stability of POFs was established from these studies. KW - Polymer optical fibers (POFs) KW - Chemiluminescence (CL) KW - Thermo-oxidative stability KW - Aging KW - Optical transmission stability PY - 2006 DO - https://doi.org/10.1016/j.polymdegradstab.2006.05.006 SN - 0141-3910 SN - 1873-2321 VL - 91 IS - 11 SP - 2605 EP - 2613 PB - Applied Science Publ. CY - London AN - OPUS4-13984 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -