TY - JOUR A1 - Stark, Wolfgang A1 - Jaunich, Matthias A1 - Mc Hugh, Jarlath T1 - Dynamic mechanical analysis (DMA) of epoxy carbon-fibre prepregs partially cured in a discontinued autoclave analogue process N2 - Epoxy carbon-fibre prepreg, Hexcel Type 6376 HTS, was investigated using Dynamic Mechanical Analysis (DMA). The DMA characteristic parameters are storage modulus E', loss modulus E' and loss factor tanδ. These parameters are ideally suited to observe the vitrification, referred to as glass transition, resulting from the cross-linking reaction. Detection of the cure state may also be achieved by determining the momentary glass transition temperature of partially cured samples. The consequent use of a multi-frequency measuring regime was used to derive the apparent activation energy for the glass transition process. Different temperature programs were also applied to monitor the curing process directly, as well as to investigate the different states of incomplete cure reached in preceding curing steps. The intention was to provide better understanding of the consequences of an interrupted autoclave curing process and to use DMA to detect the cure state achieved. With DMA, the continuation of an incomplete curing process also can be monitored. DMA measurements up to 300 °C showed, furthermore, that the final glass transition temperature was reduced by thermal degradation at high temperatures. KW - Composites KW - Epoxy KW - Cross-linking KW - Prepreg KW - Degree of cure KW - Glass transition PY - 2015 DO - https://doi.org/10.1016/j.polymertesting.2014.11.004 SN - 0142-9418 VL - 41 SP - 140 EP - 148 PB - Elsevier Science CY - Amsterdam [u.a.] AN - OPUS4-32325 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Revealing effects of chain scission during ageing of EPDM rubber using relaxation and recovery experiment N2 - Both chain scission and crosslinking reactions occur during ageing of EPDM rubber. However, with many conventional polymer analysis methods such as hardness and DMA, it is hardly possible to obtain information about the contribution of each reaction type to the measured data. For example, hardness and Tg both increase during ageing of EPDM, indicating crosslinking during ageing, but it is not clear whether this is partly counterbalanced by chain scission reactions which would lower hardness and Tg. An indication that chain scission reactions probably counteract the hardness or Tg increase by crosslinking is given by Compression Set (CS) measurements. CS exhibits a higher change than hardness or Tg, as CS increases additively through both chain scission and crosslinking reactions. In order to elucidate the share of chain scission reactions in the total degradation, a method testing relaxation and recovery behaviour using DMA equipment was applied. The method revealed the strong influence of chain scissions, leading to more pronounced relaxation and higher residual strain after compression. KW - Compression set KW - DMA KW - Nnetwork KW - Crosslinking PY - 2016 DO - https://doi.org/10.1016/j.polymertesting.2016.10.026 SN - 0142-9418 SN - 1873-2348 IS - 56 SP - 261 EP - 268 PB - Elsevier Ltd. AN - OPUS4-38012 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jaunich, Matthias ED - Brown, R. ED - Gedde, U. ED - Jaunich, Matthias T1 - Polymer Testing - Editorial N2 - Conferences and trade fairs as meeting points for technical people concerned with testing of polymers. KW - conferences KW - editorial KW - trade fair PY - 2016 DO - https://doi.org/10.1016/j.polymertesting.2016.06.020 SN - 0142-9418 VL - 2016/53 IS - 1 SP - A1 PB - Elsevier Sci Ltd. CY - Oxford, UK AN - OPUS4-37361 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Jaunich, Matthias A1 - Kömmling, Anja A1 - Wolff, Dietmar ED - Grellmann, W. ED - Langer, B. T1 - Investigations of elastomeric seals – Low temperature performance and aging behavior N2 - Due to their simple and reliable application, elastomers are used for many tasks. Many fields of application like transport, aviation and process technology, entail low temperatures where proper functionality of the employed seals has to be ensured. Therefore, understanding the low temperature behavior of elastomeric seals is important for safe seal operation to restrict the temperature application range. For all areas of application, the question of seal lifetime is also important for replacement or maintenance intervals. The lifetime is especially important in applications that allow no seal replacement. Since the seal can determine the lifetime of storage in such cases, reliable lifetime estimation is necessary for these applications, and requires an extensive knowledge of the specific aging behavior. KW - Seal KW - Rubber KW - Ageing KW - Replacement PY - 2017 SN - 978-3-319-41877-3 SN - 978-3-319-41879-7 DO - https://doi.org/10.1007/978-3-319-41879-7_30 SN - 0933-033X SN - 2196-2812 VL - 247 SP - 431 EP - 443 PB - Springer Verlag AN - OPUS4-41167 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beckmann, Jörg A1 - Schade, U. A1 - von der Ehe, Kerstin A1 - Jaunich, Matthias A1 - Wolff, Dietmar A1 - Aziz, E. F. T1 - THz and Mid IR Fourier transform spectroscopy on polyethylene irradiated with Gamma- Co60 radiation N2 - THz and mid IR spectroscopy of high molecular PE (HMW) and ultra high molecular PE (UHMW) reveals modifications of the molecular structure induced by γ-Co60 radiation. UHMW-PE and HMW-PE can be distinguished. The integral absorption in the B1u THz-region can quantitatively describe the amorphization of crystallinity. The formation of trans vinylene unsaturations and the decay of vinyl can be followed by mid IR spectroscopy T2 - IRMMW-THz 2014 - 39th International conference on infrared, millimeter, and terahertz waves CY - Tucson, Arizona, USA DA - 14.09.2014 KW - Thz and Mid IR Fourier transform spectroscopy KW - Polyethylene KW - Gamma-Co-60 radiation KW - Fourier transform spectroscopy KW - Infrared spectroscopy KW - Light absorption KW - Molecular electronic states KW - Polymers KW - MidIR Fourier transform spectroscopy KW - Terahertz spectroscopy KW - THz spectroscopy KW - γ-Co60radiation KW - HMW KW - High molecular PE KW - Ultrahigh molecular PE KW - Molecular structure modifications KW - UHMW-PE KW - HMW-PE KW - Integral absorption KW - B1uTHz-region KW - Crystallinity amorphization KW - Transvinylene unsaturation formation KW - Vinyl decay KW - Absorption KW - Radiation effects KW - Temperature measurement KW - Spectroscopy PY - 2014 UR - http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6956355&isnumber=6955975 SN - 978-1-4799-3877-3 DO - https://doi.org/10.1109/IRMMW-THz.2014.6956355 IS - IEEE Catalog No.: CFP14IMM-ART SP - 1 EP - 2 AN - OPUS4-32699 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - An approach to improve the understanding of elastomeric seals in use in storage containers N2 - Elastomers are widely used as main sealing materials in Containers for low and intermediate level radioactive waste and as additional component to metal seals in spent fuel and high active waste Containers. They are applied due to their special material properties and easy use [1]. For this application several challenging prerequisites must be met for the essential reliable Operation of the seal. T2 - 45th Annual meeting on nuclear technology CY - Frankfurt, Germany DA - 06.05.2014 PY - 2014 SN - 978-3-926956-99-6 SP - 1 EP - 4 AN - OPUS4-31250 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stark, Wolfgang A1 - Jaunich, Matthias A1 - McHugh, J. T1 - Cure state detection for pre-cured carbon-fibre epoxy prepreg (CFC) using temperature-modulated differential scanning calorimetry (TMDSC) N2 - Carbon-fibre prepregs have found widespread use in lightweight applications. They are based on a carbon-fibre fabric impregnated with reactive epoxy resin. Prepreg materials are generally pre-cured so that they have a higher molecular weight than typical resins in order to reduce resin flow, which facilitates storage and later processing properties. The measurements were carried out using commercially available materials and follow the published DMA investigations of the same material. TMDSC was used to find the correlation between curing conditions, the degree of cure and glass transition temperature. TMDSC has the advantage over standard DSC that it enables better determination of the glass transition temperature, which is often accompanied by an exothermic curing reaction, and thus overshadowed. The influence of the amplitude of temperature modulation was tested in preliminary experiments. For non-cured material a glass transition temperature of approximately 0 °C was determined; whereas for the totally cured material it was approximately 230 °C. The changes in degree of cure, temperature of actual glass transition and post-reaction are given as a function of curing time at 180 °C. The correlation between actual glass transition temperature and degree of cure is derived. KW - Prepreg KW - Carbon fibre KW - Glass transition KW - Degree of curing KW - DSC KW - TMDSC PY - 2013 DO - https://doi.org/10.1016/j.polymertesting.2013.07.007 SN - 0142-9418 VL - 32 IS - 7 SP - 1261 EP - 1272 PB - Elsevier Science CY - Amsterdam [u.a.] AN - OPUS4-29067 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stark, Wolfgang A1 - Jaunich, Matthias T1 - Investigation of ethylene/vinyl acetate copolymer (EVA) by thermal analysis DSC and DMA N2 - Two types of commercially applied Ethylene/Vinyl Acetate Copolymers (EVA) for encapsulation of photovoltaic modules were investigated by the thermal analysis methods of Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) in the temperature range from -150 °C to 200 °C. Glass transition, crystal melting and cross-linking were analyzed. The aims of the investigations were to gain more information for incoming goods control and to get information about the whole temperature dependent material properties in the investigated temperature range, starting at very low temperatures up to the crosslinking temperature region. KW - EVA KW - Thermal analysis KW - DSC KW - DMA KW - Glass transition KW - Crystal melting KW - Cross-linking PY - 2011 DO - https://doi.org/10.1016/j.polymertesting.2010.12.003 SN - 0142-9418 VL - 30 IS - 2 SP - 236 EP - 242 PB - Elsevier Ltd. CY - Amsterdam [u.a.] AN - OPUS4-23206 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arfi, W. A1 - Khan, A. A1 - Moulai, F. A1 - Agroui, K. A1 - Baretta, C. A1 - Oreski, G. A1 - Jaunich, Matthias ED - Munday, J. ED - Bermel, P. ED - Kempe, M. T1 - Optical and thermal analysis of PVB encapsulant polymer functionalized with luminescent organic dyes N2 - This work focused on the technology of luminescent down shift (LDS), with a primary aim to identify and investigate a methodology to introduce the luminescent organic dye into PVB polymer encapsulant as emergent material for photovoltaic application. For this goal, we propose to study the feasibility to implement the LDS functionality and to identify suitability of available luminescent to be incorporated into the host polymer encapsulant material. The first step to this direction was through a comprehensive optical study of Violet 570 (V) organic dye in ethanol solvent. The methodology and experimental conditions such as laboratory polymer preparation and luminescence dye concentration were presented. Also, the emergent polymer encapsulant sheets were characterized by using optical and thermal analysis techniques. The absorption spectrum of the prepared PVB material shifts towards longer wavelengths, with increasing organic dye concentration. T2 - New Concepts in Solar and Thermal Radiation Conversion and Reliability CY - San Diego, California, United States DA - 19.08.2018 KW - Photovoltaic KW - Encapsulation KW - Luminescence PY - 2018 SN - 9781510620902 DO - https://doi.org/10.1117/12.2318428 SN - 1996-756X SP - Paper OH, 1 PB - SPIE CY - Bellingham, Washington, USA AN - OPUS4-47165 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grelle, Tobias A1 - Wolff, Dietmar A1 - Jaunich, Matthias T1 - Temperature-dependent leak tightness of elastomer seals after partial and rapid release of compression N2 - A device has been designed, built and tested that allows the investigation of effects of dynamic loads on the leak tightness of elastomer seals at low temperatures. With the test setup, the compression of the tested seal can be reduced by a defined degree in a time period of less than 1 s. For the evaluation of the leak tightness, leakage rates can be determined. It was shown that the rapid partial release of an elastomer seal leads to its failure already at the beginning of the rubber–glass transition and, therefore, at significantly higher temperatures than the loss of leak tightness observed under static conditions. KW - Sealing material KW - Elastomer KW - Dynamic loading KW - Low temperature behaviour KW - Leakage rate PY - 2015 DO - https://doi.org/10.1016/j.polymertesting.2015.09.009 SN - 0142-9418 VL - 48 SP - 44 EP - 49 PB - Elsevier Ltd. CY - Amsterdam [u.a.] AN - OPUS4-34445 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Ageing of HNBR, EPDM and FKM O-rings N2 - HNBR, EPDM and FKM O-rings were aged uncompressed and compressed at 75 °C, 100 °C, 125 °C and 150 °C for up to 1 year. HNBR exhibited the strongest ageing effects with high increases of hardness and glass transition temperature. Furthermore, heterogeneous ageing caused by diffusion-limited oxidation effects had a significant influence for HNBR at ageing temperatures of 125 °C and 150 °C. EPDM showed similar property changes as HNBR, but less pronounced. FKM displayed only minor ageing effects. O-rings aged in compression exhibited considerable compression set (CS). CS data was used for a time-temperature shift and resulting master curve construction. Leakage rate measurements showed that O-rings can remain leak tight under static conditions even if material properties have already deteriorated strongly. N2 - HNBR-, EPDM- und FKM-O-Ringe wurden unverpresst und verpresst für bis zu 1 Jahr bei 75 °C, 100 °C, 125 °C und 150 °C gealtert. HNBR wies mit hohen Anstiegen von Härte und Glasübergangstemperatur die stärksten Alterungseffekte auf. Weiterhin hatte heterogene Alterung aufgrund von diffusionsbegrenzten Oxidationseffekten einen wesentlichen Einfluss auf HNBR bei Alterungstemperaturen von 125 °C und 150 °C. EPDM zeigte ähnliche Eigenschaftsänderungen wie HNBR, allerdings schwächer ausgeprägt. FKM wies nur geringfügige Alterungseffekte auf. O-Ringe, die verpresst gealtert wurden, hatten eine starke bleibende Verformung (DVR). Die gemessenen DVRWerte wurden für eine Zeit-Temperatur-Verschiebung und die Konstruktion einer Masterkurve genutzt. Leckageratenmessungen zeigten, dass O-Ringe unter statischen Bedingungen dicht bleiben können, auch wenn die Materialeigenschaften schon stark degradiert sind. KW - Aging KW - Degradation KW - Leakage KW - Compression KW - Seal PY - 2016 SN - 0022-9520 SN - 0948-3276 VL - 69 IS - 4 SP - 36 EP - 42 PB - Hüthig CY - Heidelberg, Germany AN - OPUS4-36336 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Silbernagl, Dorothee A1 - Kömmling, Anja A1 - Zaghdoudi, Maha A1 - Ghasem Zadeh Khorasani, Media A1 - Jaunich, Matthias T1 - Data-driven nanomechanical study of filled fluoroelastomer aged in air and hydrogen atmosphere N2 - Fluoroelastomer (FKM) composites are typically used as sealing materials in challenging non-ambient environments. Depending on the environment, two main aging mechanisms, chemical aging, and physical aging, can be identified. Chemical aging, the degradation of the elastomer, is present for example in thermal-oxidative conditions and can be directly observed as it affects the bulk. Physical aging, relaxation and rearrangement of the elastomers segmental conformation is commonly observed at elevated temperatures and effects predominantly the elastomer interphase. As a highly localized nanoscopic effect it is usually observed indirectly by phenomological approaches and not systematically understood. In this study, as a typical example for chemical aging, filled FKM was aged in air (150°C, 100 days). Physical aging of FKM was realized by exposure to chemically inert H2 (150°C, 50 bar, 100 days), since temperature and gas-induced swelling is known to promote physical aging. The effects of both conditions are directly compared with the initial unaged material. We use atomic force microscopy (AFM) force spectroscopy as a method to resolve nanoscopic heterogeneous FKM. With this method the effect of aging on the spatially distinguishable material phases was directly observed. In thermal oxidative aged FKM the matrix shows a decrease in van der Waals interactions and stiffness, indicating dehydrofluorination and chain scission. In H2 aged FKM, the development of an immobilized amorphous interphase (IAP) was observed, indicating physical aging. By additionally evaluating a larger data set with supervised machine learning, these observations were validated for a larger, statistically representative sample area, allowing conclusions to be drawn about the macroscopic behaviour of the material. KW - Fluoroelastomer KW - Atomic force microscopy KW - Data-driven KW - Hydrogen KW - Ageing mechanism KW - Physical aging KW - Polymer interphase PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-648154 DO - https://doi.org/10.1016/j.polymdegradstab.2025.111715 SN - 0141-3910 VL - 242 SP - 1 EP - 10 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-64815 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kömmling, Anja A1 - von der Ehe, Kerstin A1 - Wolff, Dietmar A1 - Jaunich, Matthias T1 - Effect of high-dose gamma irradiation on (U)HMWPE neutron shielding materials N2 - High and ultra-high molecular weight polyethylenes were gamma-irradiated with doses up to 600 kGy. The changes in the material properties were analysed using DSC, DMA, IR spectroscopy, as well as measurements of density and insoluble content. The irradiation led to an increase of the degree of crystallinity because of chain scissions during irradiation, leading to shorter and thus more mobile chains. Both the plateau value of the shear modulus G′ and the insoluble content increased with Irradiation dose, indicating the formation of additional crosslinks. Furthermore, IR spectroscopy revealed irradiation induced oxidation and the formation of double bonds, indicating that some of the hydrogen atoms responsible for the neutron shielding capability have been released. KW - Ultra high molecular weight KW - Polyethylene KW - Gamma irradiation KW - Crosslinking KW - Oxidation PY - 2018 DO - https://doi.org/10.1016/j.radphyschem.2017.02.014 SN - 0969-806X VL - 142 SP - 29 EP - 33 PB - Elsevier AN - OPUS4-42941 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jaunich, Matthias A1 - Stark, Wolfgang A1 - Wolff, Dietmar T1 - A new method to evaluate the low temperature function of rubber sealing materials N2 - A new method for the evaluation of the low temperature properties of rubber materials is presented. The method emulates the standardized compression set measurement, which is frequently used for sealing materials, but can be performed within a considerably shorter time. The results are compared with the standard test and found to be qualitatively the same. Slight differences are discussed on the basis of the differences in the measurement procedures. Further data evaluation is done by fitting functions to describe the material behaviour. KW - Sealing material KW - Elastomer KW - Compression set KW - Dynamic mechanical analysis KW - Low temperature behaviour PY - 2010 DO - https://doi.org/10.1016/j.polymertesting.2010.07.006 SN - 0142-9418 VL - 29 IS - 7 SP - 815 EP - 823 PB - Elsevier Science CY - Amsterdam [u.a.] AN - OPUS4-21914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jaunich, Matthias A1 - Böhning, Martin A1 - Braun, Ulrike A1 - Teteris, G. A1 - Stark, W. T1 - Investigation of the curing state of ethylene/vinyl acetate copolymer (EVA) for photovoltaic applications by gel content determination, rheology, DSC and FTIR N2 - The cure behaviour of a specific ethylene vinyl acetate material as used for encapsulation of photovoltaic modules was analysed by rheometer, differential scanning calorimetry and Fourier transform infrared spectroscopy to test for a suitable replacement for the laborious determination of gel content. The results show that all applied methods are capable of describing the effects of the cross-linking process. Some provide results very similar to those yielded by analysis of the insoluble content, but the question remains as to whether indirect methods should be preferred over the direct measurement of physical properties, e.g. as performed by the curemeter. A material stored for one year was also tested to demonstrate the effect of extended storage on cure behaviour and how this is detected by different methods. This complements the other methods, which were clearly able to detect the different cure behaviour of the aged EVA, whereas determination of the gel content could not. KW - Photovoltaic cell encapsulation KW - EVA KW - Incoming goods control KW - Insoluble content KW - Rheometer PY - 2016 DO - https://doi.org/10.1016/j.polymertesting.2016.03.013 SN - 0142-9418 VL - 52 IS - 1 SP - 133 EP - 140 PB - Elsevier Ltd. CY - Oxford, UK AN - OPUS4-35918 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Effects of heterogeneous aging in compressed HNBR and EPDM O-ring seals N2 - Seals used in containers for dangerous goods need to maintain leak tightness for several decades. For investigating the change in seal material properties during aging, a comprehensive aging program on both uncompressed and compressed EPDM and HNBR seals was started. In order to obtain results closely related to practical conditions, O-rings with a full-scale cord diameter of 10 mm were aged. However, this set-up can lead to heterogeneous aging caused by diffusion-limited oxidation (DLO) effects. These effects depend on material, dimensions, time and temperature. Heterogeneous aging results in distorted bulk properties such as compression stress relaxation and compression set (CS) suggesting that HNBR has better performance than EPDM at 150 °C but which is not the case at 100 °C. The presence of heterogeneous material properties was shown by hardness measurements across the seal cross-section. If DLO-affected data is excluded, extrapolations of CS data are possible using time-temperature shifts and Arrhenius graphs. Exemplary CS values of 50 % and 80 % would be reached after approx. 10 years and 29 years, respectively for HNBR and after approx. 400 years and 1100 years, respectively for EPDM. KW - Ageing KW - Rubber KW - Compression KW - DLO KW - Extrapolation KW - Lifetime prediction PY - 2016 DO - https://doi.org/10.1016/j.polymdegradstab.2016.01.012 VL - 126 SP - 39 EP - 46 PB - Elsevier Science CY - Oxford AN - OPUS4-35775 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Influence of gamma irradiation on low temperature properties of rubber seal materials N2 - In many fields the function of seal materials is required at low temperatures. Therefore the understanding of failure mechanisms at low temperatures is of high importance. In some applications elastomeric seals are used in environments with increased irradiation backgrounds, as e.g. in containers for radioactive waste. This paper reports on the influence of gamma irradiation on the low temperature properties of different fluorocarbon rubber (FKM) materials. The samples were irradiated with gamma doses of up to 600 kGy and the induced changes of material properties were tested by methods sensitive to the rubber-glass transition, like DSC and DMA. Additionally, compression set measurements were performed to give information about recovery behaviour at low temperatures. KW - Seal KW - O-ring KW - Low temperature KW - Gamma irradiation KW - Compression set KW - Dichtungen KW - O-Ringe KW - Tiefe Temperatur KW - Gamma-Bestrahlung KW - Druckverformungsrest PY - 2015 SN - 0948-3276 SN - 0022-9520 VL - 68 IS - 6 SP - 85 EP - 89 PB - Hüthig CY - Heidelberg AN - OPUS4-33552 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jaunich, Matthias T1 - The average number of references per article published in Polymer Testing over the years N2 - This Editorial is focussed on the changes in the number of references per article published in Polymer Testing from 1980 until today. To set in into context with other changes a comparison with the impact factor of Polymer Testing is presented. KW - Reference KW - Editorial KW - Impact factor KW - Changes with time PY - 2018 DO - https://doi.org/10.1016/j.polymertesting.2018.05.034 SN - 0142-9418 VL - 68 SP - A1 EP - A2 PB - Elsevier AN - OPUS4-45212 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jaunich, Matthias A1 - Stark, Wolfgang T1 - Einfluss der Härtung auf die Materialeigenschaften eines Harnstoffharzes N2 - Über die in der Technik weit verbreitete typisierte Harnstoffformmasse UF 131.5, ein Aminoplast, wird berichtet, dass sie im Zuge der thermisch aktivierten Vernetzungsreaktion wegen "Überhärtung" mangelhafte Eigenschaften annimmt. Zur Verifizierung dieses Effektes werden mithilfe der Ultraschall-Prozesskontrolle gezielt Proben unterschiedlicher Aushärtegrade hergestellt. Sie werden mit verschiedenen Methoden, wie der "Kochprobe" und der Thermoanalyse, charakterisiert und auf ihre Materialeigenschaften untersucht. Dabei zeigt sich ein deutlicher Einfluss der Härtezeit auf die Glasübergangstemperatur der Formmasse. In den mechanischen Eigenschaften ist eine Veränderung allerdings nur in der Schlagzähigkeit festzustellen, die sich mit steigender Härtezeit sogar wesentlich verbessert. PY - 2009 SN - 0025-5300 VL - 51 IS - 11-12 SP - 828 EP - 834 PB - Hanser CY - München AN - OPUS4-20566 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Goral, Milan A1 - Sagradov, Ilja A1 - Wolff, Dietmar A1 - Völzke, Holger T1 - Aging investigations of metal seals used in containers for interim storage of spent fuel N2 - For bolted casks for used fuel and high level waste the sealing system has an important impact of ensuring safe enclosure of the inventory The used metal seals show some changes over time which have been addressed for nearly 15 years in running experiments at BAM The observed changes are temperature de pendent and therefore it is expected that test s at higher temperature allow for an acceleration of the effects and ideally the proposal of an ageing model covering the expected time of use . Nevertheless, questions concerning the influence of the experimental approach on the results and effects taking place at the initial days of ageing remain. To address these a new project was launched to give a better understanding of the seal behavior. T2 - PVP2024, Pressure Vessels & Piping Conference CY - Bellevue, WA, USA DA - 29.07.2024 KW - Metal seal KW - Aging KW - Interim storage PY - 2024 SN - 978-0-7918-8851-3 SP - 1 EP - 4 PB - ASME AN - OPUS4-61357 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -