TY - JOUR A1 - Tomiak, F. A1 - Schartel, Bernhard A1 - Wolf, M. A1 - Drummer, D. T1 - Particle Size Related Effects of Multi-Component Flame-Retardant Systems in poly(butadiene terephthalate) N2 - Aluminum tris (diethylphosphinate) (AlPi) is known to have an efficient flame-retardant effect when used in poly(butadiene terephthalates) (PBT). Additionally, better flame-retardant effects can be achieved through the partial substitution of AlPi by boehmite in multi-component systems, which have been shown to be an effective synergist due to cooling effects and residue formation. Although the potential of beneficial effects is generally well known, the influence of particle sizes and behavior in synergistic compositions are still unknown. Within this paper, it is shown that the synergistic effects in flammability measured by limiting oxygen index (LOI) can vary depending on the particle size distribution used in PBT. In conducting thermogravimetric analysis (TGA) measurements, it was observed that smaller boehmite particles result in slightly increased char yields, most probably due to increased reactivity of the metal oxides formed, and they react slightly earlier than larger boehmite particles. This leads to an earlier release of water into the system enhancing the hydrolysis of PBT. Supported by Fourier transformation infrared spectroscopy (FTIR), we propose that the later reactions of the larger boehmite particles decrease the portion of highly flammable tetrahydrofuran in the gas phase within early burning stages. Therefore, the LOI index increased by 4 vol.% when lager boehmite particles were used for the synergistic mixture. KW - Flame retardants KW - Aluminum diethylphosphinate KW - Boehmite KW - Poly(butadiene terephthalates) (PBT) KW - Mechanical properties PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509286 DO - https://doi.org/10.3390/polym12061315 SN - 2073-4360 VL - 12 IS - 6 SP - 1315 PB - MDPI AN - OPUS4-50928 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Morys, Michael A1 - Häßler, Dustin A1 - Krüger, Simone A1 - Schartel, Bernhard A1 - Hothan, Sascha T1 - Beyond the standard time-temperature curve: Assessment of intumescent coatings under standard and deviant temperature curves N2 - Nowadays there are intumescent coatings available for diverse applications. There is no established assessment of their protection performance besides the standard time-temperature curve, but natural fire scenarios often play an important role. A reliable straightforward performance-based assessment is presented. The effective thermal conductivity per thickness is calculated based on intermediate-scale fire tests. The optimum thermal insulation, the time to reach it, and the time until contingent failure of the coating are used for an assessment independent of the heating curve. The procedure was conducted on four different commercially intumescent coatings for steel construction, one solvent-based, one waterborne, one epoxy-based, and a bandage impregnated with a waterborne coating. The performance was studied under four different but similar shaped heating curves with different maximum temperatures (standard time-temperature curve, hydrocarbon curve and two self-designed curves with reduced temperature). The thermal protection performance is crucially affected by the residue morphology. Therefore, a comprehensive morphology analysis, including micro-computed tomography and scanning electron microscopy, was conducted on small-scale residues (7.5 x 7.5 cm2). Two different types of inner structures and the residue surface after different heat exposures were discussed in terms of their influence on thermal protection performance. KW - Intumescence KW - Coating KW - Computed tomography KW - Small scale KW - Heating curves KW - Residue morphology PY - 2020 DO - https://doi.org/10.1016/j.firesaf.2020.102951 SN - 0379-7112 VL - 112 SP - 102951 PB - Elsevier Ltd. AN - OPUS4-50334 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Battig, Alexander A1 - Markwart, J. C. A1 - Wurm, F. R. A1 - Schartel, Bernhard T1 - Sulfur's role in the flame retardancy of thio-ether–linked hyperbranched polyphosphoesters in epoxy resins N2 - Hyperbranched polyphosphoesters are promising multifunctional flame retardants for epoxy resins. These polymers were prepared via thiol-ene polyaddition reactions. While key chemical transformations and modes of actions were elucidated, the role of sulfur in the chemical composition remains an open question. In this study, the FR-performance of a series of phosphorus-based flame retardant additives with and without sulfur (thioethers or sulfones) in their structure are compared. The successful synthesis of thio-ether or sulfone-containing variants is described and verified by 1H and 31P NMR, also FTIR and MALDI-TOF. A decomposition process is proposed from pyrolytic evolved gas analysis (TG-FTIR, Py-GC/MS), and flame retardancy effect on epoxy resins is investigated under pyrolytic conditions and via fire testing in the cone calorimeter. The presence of sulfur increased thermal stability of the flame retardants and introduced added condensed phase action. Likely, Sulfur radical generation plays a key role in the flame-retardant mode of action, and sulfones released incombustible SO2. The results highlight the multifunctionality of the hyperbranched polymer, which displays better fire performance than its low molar mass thio-ether analogue due to the presence of vinyl groups and higher stability than its monomer due to the presence of thio-ether groups. KW - Phosphoester KW - Hyperbranched KW - Sulfur KW - Thio-ether KW - Flame retardant KW - Epoxy resin PY - 2020 DO - https://doi.org/10.1016/j.eurpolymj.2019.109390 SN - 0014-3057 VL - 122 SP - 109390 PB - Elsevier Ltd. AN - OPUS4-50238 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Turski Silva Diniz, Analice A1 - Huth, Christian A1 - Schartel, Bernhard T1 - Dripping and decomposition under fire: Melamine cyanurate vs. glass fibres in polyamide 6 N2 - Manipulating the melt dripping of thermoplastics makes a fire scenario more or less dangerous. Yet, a detailed understanding of this phenomenon has remained a question mark in studies of the flammability of plastics. In this work, the individual and collective impacts of additives on the dripping behaviour of polyamide 6 (PA6) were studied. A set of materials compounded with melamine cyanurate (MCA) and glass fibre (GF) was investigated. Under UL 94 vertical test conditions, the dripping during first and second ignition was quantified and investigated in detail. The number, size and temperature of the drops were addressed, and the materials and their drops evaluated with respect to such aspects as their averaged molecular weight, thermal decomposition and rheological properties. PA6 with V-2 classification improved to V-0 with the addition of MCA, and achieved HB in the presence of GF. PA6/GF/MCA achieved V-2. Non-flaming drops of PA6/MCA consisted of oligomeric fragments. Flaming drops of PA6/GF showed a more pronounced decomposition of PA6 and an increased GF content. The dripping behaviour of PA6/GF/MCA can be understood as a combination of the influence of both additives. The results showed nicely that dripping under fire is neither a straightforward material property nor a simple additive influence, but the complex response of the material influenced by the interaction and competition of different phenomena. KW - Dripping KW - UL 94 KW - Polyamide 6 KW - Melamine cyanurate KW - Glass fibre KW - Flame retardant PY - 2020 DO - https://doi.org/10.1016/j.polymdegradstab.2019.109048 SN - 0141-3910 VL - 171 SP - 109048 PB - Elsevier Ltd. AN - OPUS4-50239 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zirnstein, Benjamin A1 - Schulze, Dietmar A1 - Schartel, Bernhard T1 - Combination of phosphorous flame retardants and aluminum trihydrate in multicomponent EPDM composites N2 - Ethylene propylene diene monomer (EPDM) Rubbers with the flame retardants tris(2-ethylhexyl)phosphate, ammonium polyphosphate, polyaniline, and aluminum trihydroxide were prepared and analyzed in this study. The homogenous dispersion of the fillers in the rubber matrix was confirmed by scanning electron microscope. To investigate the interplay of the different flame retardants, the flame retardants were varied systematically. The comprehensive study sought combinations of flame retardants that allow high loadings of flame retardants without deterioration of the physical and mechanical properties of the EPDM rubber. The eight EPDM rubbers were investigated via thermogravimetric analysis and pyrolysis gas chromatography coupled with a mass spectrometer (Py GC/MS) to investigate the potential synergistic effects. In the Py-GC/MS experiments, 27 pyrolysis products were identified. Furthermore, UL 94, limiting oxygen index, FMVSS 302, glow wire tests, and cone calorimeter tests were carried out. In the cone calorimeter test the EPDM rubbers R-1AP and R-1/2P achieved an increase in residue at flameout of 76% and a reduction in total heat evolved of about 35%. Furthermore, the compounds R-1AP and R-1/2P achieved a reduction in MARHE to about 150 kW m−1, a reduction of over 50% compared to the unprotected rubber R. KW - EPDM KW - Rubber KW - Aluminum hydroxide (ATH) KW - Phosphorous flame retardant PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-502859 DO - https://doi.org/10.1002/pen.25280 SN - 1548-2634 VL - 60 IS - 2 SP - 267 EP - 280 PB - Wiley AN - OPUS4-50285 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Günther, Martin T1 - Flame retardancy of polyurethanes N2 - Polyurethanes (PU) represent one of the most versatile classes of plastics. They are processed and used as thermoplastic, elastomer, and thermoset. The requirements regarding flammability are correspondingly versatile. Depending on the material and the field of application, specific fire tests have to be fulfilled. This paper describes the different concepts used to fulfil these requirements by choosing the right raw materials and flame retardants. KW - Polyurethane KW - Flame retardant KW - Foam KW - Flammability KW - Pyrolysis KW - Cone calorimeter PY - 2020 VL - 17 IS - 1 SP - 44 EP - 48 PB - Dr. Gupta AN - OPUS4-50737 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rabe, Sebastian A1 - Klack, Patrick A1 - Bahr, Horst A1 - Schartel, Bernhard T1 - Assessing the fire behavior of woods modified by N-methylol crosslinking, thermal treatment, and acetylation N2 - Wood products are often treated by different techniques to improve their longevity when used as building materials. Most of the time, the goal is to increase their resistance to weathering effects, deformations in material dimensions or biotic decomposition. These wood treatment techniques have a significant impact on pyrolysis and burning behavior. The general effects of three different common wood treatments on flame retardancy were investigated by comparing treated woods with their untreated counterparts and with other kinds of wood. While the acetylation of beech leads to a slightly increased fire hazard, the thermal treatment of wood and crosslinking of cellulose microfibrils dimethyloldihydroxy-ethyleneurea show a limited flame retarding effect. Switching to woods with a higher lignin content, and thus higher char yield, however, results in a more pronounced improvement in flame retardancy performance. This article delivers a comprehensive and balanced assessment of the general impact of different wood modifications on the fire behavior. Further, it is a valuable benchmark for assessing the flame retardancy effect of other wood modifications. KW - Acetylation KW - Cone claorimeter KW - DMDHEU KW - Heat of combustion KW - Thermal treatment KW - Wood modification PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-507397 DO - https://doi.org/10.1002/fam.2809 SN - 1099-1018 SN - 0308-0501 VL - 44 IS - 4 SP - 530 EP - 539 PB - Wiley Online Libary AN - OPUS4-50739 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ma, S. A1 - Xiao, Y. A1 - Zhou, F. A1 - Schartel, Bernhard A1 - Chan, Yin Yam A1 - Korobeinichev, O. P. A1 - Trubachev, S. A. A1 - Hu, W. A1 - Ma, C. A1 - Hu, Y. T1 - Effects of novel phosphorus-nitrogen-containing DOPO derivative salts on mechanical properties, thermal stability and flame retardancy of flexible polyurethane foam N2 - In this work, a series of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivative salts containing phosphorus and nitrogen were synthesized, and their effects on mechanical properties, thermal stability and flame retardancy of flexible polyurethane foam (FPUF) were investigated. Studies have shown that the addition of DOPO derivatives will increase the tensile strength, compression set, and compression hardness of FPUF, but it will lead to a decrease in elongation at break. Thermogravimetric analysis showed that the initial decomposition temperature of FPUF containing DOPO derivatives was reduecd, but the char reside was significantly improved. A series of combustion tests indicated that the addition of DOPO derivative salts can improve the flame retardancy of FPUF, of which 10-hydroxy-9,10-dihydro-9-oxa-10 phosphaphenanthrene-10-oxide dicyandiamide salt (D-DICY) exhibited the best flame retardancy. When the load of D-DICY was 20 phr, the limiting oxygen index (LOI) of foam reached 24.5%, and the peak heat release rate and total heat release were decreased by 55.7% and 52.9%, respectively. Furthermore, based on the analysis of the gas phase combustion products and the char residue of the condensed phase, the possible flame retardant mechanism was proposed. KW - Flexible polyurethane foam KW - DOPO derivative salts KW - Mechanical properties KW - Thermal stability KW - Flame retardancy PY - 2020 DO - https://doi.org/10.1016/j.polymdegradstab.2020.109160 SN - 0141-3910 VL - 177 SP - 109160 PB - Elsevier Ltd. AN - OPUS4-50740 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Günther, Martin T1 - Flammschutz von Polyurethanen N2 - Polyurethane (PU) bilden eine der vielseitigsten Klassen der Polymerwerkstoffe. Kein anderer Kunststoff wird sowohl als Thermoplast, als Elastomer wie auch als Duroplast verarbeitet und eingesetzt. Entsprechend vielfältig sind auch die Anforderungen an den Flammschutz. Je nach Material und Anwendung müssen spezifische Brandnormen erfüllt werden. Der vorliegende Aufsatz gibt einen Überblick über die verfügbaren Ansätze, um durch geeignete Auswahl der Rohstoffe und der Flammschutzmittel diese verschiedensten Anforderungen an das Brandverhalten zu erfüllen. KW - Polyurethan KW - Flammschutz KW - Pyrolyse KW - Schaum KW - Cone calorimeter PY - 2020 VL - 20 IS - 1 SP - 48 EP - 53 PB - Dr. Gupta AN - OPUS4-50736 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pappalardo, Salvatore A1 - Russo, Pietro A1 - Acierno, Domenico A1 - Rabe, Sebastian A1 - Schartel, Bernhard T1 - The synergistic effect of organically modified sepiolite in intumescent flame retardant polypropylene N2 - The pyrolysis, flammability and fire behavior of polypropylene (PP) containing an intumescent flame retardant and sepiolite nanoparticles were investigated by performing thermogravimetry, oxygen index (LOI), UL-94, and cone calorimeter tests. The combination of 0.5 wt% of premodified sepiolite (OSEP) with 12 wt% of a commercial intumescent flame retardant showed a clear synergy in LOI, UL-94 ranking and peak heat release rate. The ternary formulation achieved a V-0 classification and, consequently, allowed a reduction in the amount of flame retardant necessary to achieve this result. Whereas OSEP and pristine sepiolite nanoparticles (SEP) affect the performance in PP nanocomposites quite similarly, OSEP outperformed SEP in the combination with intumescent flame retardant. The cone calorimeter results and dynamic rheological measurements confirmed the synergistic effect between the nanofiller and the flame retardant resulting from the improved properties of the residual protective layer. KW - Polypropylene KW - Intumescent flame retardant KW - Sepiolite KW - Cone calorimetry KW - Low oxygen index PY - 2016 DO - https://doi.org/10.1016/j.eurpolymj.2016.01.041 SN - 0014-3057 VL - 76 SP - 196 EP - 207 PB - Elsevier AN - OPUS4-35854 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Perret, Birgit A1 - Dittrich, Bettina A1 - Ciesielski, M. A1 - Krämer, J. A1 - Müller, P. A1 - Altstädt, V. A1 - Zang, L. A1 - Döring, M. T1 - Flame retardancy of polymers: the role of specific reactions in the condensed phase N2 - Condensed-phase mechanisms play a major role in fire-retardant polymers. Generations of development have followed the concept of charring to improve fire properties. Whereas the principal reactions are believed to be known, the specific description for multicomponent systems is lacking, as is the picture across different systems. A two-step approach is proposed in general, and also presented in greater detail. The second step covers the specific reactions controlling charring, whereas the actual reactants are provided in the preceding step. This model consistently incorporates the variety of structure–property relationships reported. A comprehensive case study is presented on seven phosphorus flame retardants in two epoxy resins to breathe life into the two-step approach. KW - Charring KW - Epoxy KW - Flame retardancy KW - Pyrolysis KW - Thermogravimetric analysis (TGA) PY - 2016 DO - https://doi.org/10.1002/mame.201500250 SN - 1438-7492 SN - 1439-2054 VL - 301 IS - 1 SP - 9 EP - 35 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-35273 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 - Hörold, Andreas A1 - Schartel, Bernhard A1 - Trappe, Volker A1 - Gettwert, V. A1 - Korzen, Manfred T1 - Protecting the structural integrity of composites in fire: Intumescent coatings in the intermediate scale N2 - The fire behaviour of light-weight material used in structural applications is regarded as the main challenge to be solved for mass transportation. The task is to perform realistic experiments, including a mechanical test scenario under fully developed fires, to improve the material's reliability in structural applications. Our approach utilises an intermediate-scale test set-up (specimen size 500 × 500 mm) to apply realistic compressive loads and fully developed fires directly to one side of a carbon-fibre-reinforced sandwich composite. Three different intumescent coatings were applied to sandwich structures and compared to a bench-scale study. The results emphasise intumescent coatings as a promising method to sustain fire resistance, multiplying the time to failure. Nevertheless, the realistic intermediate-scale test using severe direct flame application underlines the extremely short failure times when the actual composite components are tested without any additional insulation. KW - Carbon-fibre-reinforced KW - Fire stability KW - High-temperature properties KW - Mechanical testing KW - Fully developed fire KW - Post-crash scenario PY - 2015 DO - https://doi.org/10.1177/0731684415609791 SN - 0731-6844 SN - 1530-7964 VL - 34 IS - 24 SP - 2029 EP - 2044 PB - Technomic Publ. Co. CY - Westport, Conn. AN - OPUS4-35120 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Günther, Martin A1 - Lorenzetti, A. A1 - Schartel, Bernhard T1 - From Cells to Residues: Flame-Retarded Rigid Polyurethane Foams N2 - Rigid polyurethane foams (RPUFs) exhibit short times to ignition as well as rapid flame spread and are therefore considered to be hazardous materials. This paper focuses on the fire phenomena of RPUFs, which were investigated through a multimethodological approach. Water-blown polyurethane (PUR) foams without flame retardants (FRs) as well as waterblown PUR foams containing triethyl phosphate as a gas phase-active FR were examined. The aim of this study is to clarify the influence of the FR on the fire phenomena during combustion of the foams. Additionally, materials’ densitieswere varied to range from 30 to 100 kg/m3. Thermophysical properties were studied bymeans of thermogravimetry; fire behavior and flammability were investigated via cone calorimeter and limiting Oxygen index, respectively. During the cone calorimeter test, the temperature development inside the burning specimens was monitored with thermocouples, and cross sections of quenched specimens were examined visually, giving insight into the morphological changes during combustion. The present paper delivers a comprehensive study, illuminating phenomena occurring during foam combustion and the influence of a FR active in the gas phase. The superior fire performance of flameretarded PUR foams was found to be based on flame inhibition, and on increased char yield leading to a more effective protective layer. It was proven that in-depth absorption of radiation is a significant factor for estimation of time to ignition. Cross sections investigated with the electron scanning microscope exhibited a pyrolysis front with an intact foam structure underneath. The measurement of temperature development inside burning specimens implied a shift of burning behavior towards that of non-cellular materials with rising foam density. KW - Polyurethane KW - Rigid foams KW - Fire behavior PY - 2020 DO - https://doi.org/10.1080/00102202.2019.1634060 SN - 0010-2202 SN - 1563-521X VL - 192 IS - 12 SP - 2209 EP - 2237 PB - Taylor & Francis AN - OPUS4-51483 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Günther, Martin A1 - Levchik, S. V. A1 - Schartel, Bernhard T1 - Bubbles and collapses: Fire phenomena of flame-retarded flexible polyurethane foams N2 - Flexible polyurethane foams (FPUF) are easy to ignite and exhibit rapid flame spread. In this paper, the fire phenomena of two standard foam formulations containing tris (1,3-dichloro-2-propyl) phosphate (FR-2) and a halogen-freepoly (ethyl ethylene phosphate) (PNX), respectively, as flame retardants are compared. A multimethodological approach is proposed which combines standard fire tests as well as new investigatory approaches. The thermophysical properties of the foams were determined by thermogravimetric analysis (TG), reaction to small flames was studied by means of the limiting oxygen index (LOI) and UL 94 HBF test, and the burning behavior was investigated with the cone calorimeter. Further, temperature development in burning cone calorimeter samples was monitored using thermocouples, and rheological measurements were performed on pyrolyzed material, delivering insight into the dripping behavior of the foams. This paper gives comprehensive insight into the fire phenomena of flame-retarded FPUFs that are driven by the two-step decomposition behavior of the foams. LOI and UL 94 HBF tests showed a reduced flammability and reduced tendency to drip for the flame-retarded foams. TG and cone calorimeter measurements revealed that the two-step decomposition behavior causes two stages during combustion, namely structural collapse and pool fire. The flame-retardant mode of action was identified to take place primarily during the foam collapse and be based mainly on flame inhibition. However, some condensed-phase action was been measured, leading to significantly increased melt viscosity and improved dripping behavior for foams containing PNX. KW - Burning behavior KW - Flame retardant KW - Flexible PU foam PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-512145 DO - https://doi.org/10.1002/pat.4939 SN - 1042-7147 SN - 1099-1581 VL - 31 IS - 10 SP - 2185 EP - 2198 PB - Wiley Online Libary AN - OPUS4-51214 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Goedecke, Caroline A1 - Dittmann, Daniel A1 - Eisentraut, Paul A1 - Wiesner, Yosri A1 - Schartel, Bernhard A1 - Klack, Patrick A1 - Braun, Ulrike T1 - Evaluation of thermoanalytical methods equipped with evolved gas analysis for the detection of microplastic in environmental samples N2 - Microplastic particles are currently detected in almost all environmental compartments. The results of detection vary widely, as a multitude of very different methods are used with very different requirements for analytical validity. In this work four thermoanalytical methods are compared and their advantages and limitations are discussed. One of them is thermal extraction-desorption gas chromatography mass spectrometry (TED-GC/MS), an analysis method for microplastic detection that has become established in recent years. In addition, thermogravimetric analysis coupled with Fourier-transform infrared spectroscopy (TGA-FTIR) and mass spectrometry (TGA-MS) were applied, two methods that are less common in this field but are still used in other research areas. Finally, microscale combustion calorimeter (MCC) was applied, a method not yet used for microplastic detection. The presented results are taken from a recently published interlaboratory comparison test by Becker et al. (2020). Here a reference material consisting of suspended matter and specified added polymer masses was examined, and only the results of the recoveries were presented. In the present paper, however, the results for the individual polymers are discussed in detail and individual perspectives for all instruments are shown. It was found that TED-GC/MS is the most suitable method for samples with unknown matrix and unknown, variable kinds and contents of microplastic. TGA-FTIR is a robust method for samples with known matrix and with defined kinds of microplastic. TGA-MS may offer a solution for the detection of PVC particles in the future. MCC can be used as a very fast and simple screening method for the identification of a potential microplastic load of standard polymers in unknown samples. KW - Microplastic KW - TED-GC/MS KW - TGA-MS KW - TGA-FTIR KW - MCC KW - Thermal analysis PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-516687 DO - https://doi.org/10.1016/j.jaap.2020.104961 VL - 152 SP - 104961 PB - Elsevier B.V. AN - OPUS4-51668 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Battig, Alexander A1 - Sanchez-Olivares, G. A1 - Rockel, Daniel A1 - Maldonado-Santoyo, M. A1 - Schartel, Bernhard T1 - Waste not, want not: The use of leather waste in flame retarded EVA N2 - Leather is among the most ancient, widely used materials worldwide. Industrial-scale leather production produces large quantities of organic waste attained during shaving and buffing steps during processing. In this study, leather wastes (LW) are used as fillers in flame retarded polymer composites. LW is investigated as a multifunctional bio-filler that enhances the fire performance of flame retarded poly(ethylene–vinyl acetate) (EVA) containing phosphorus flame retardants (P-FRs) ammonium polyphosphate (APP) or a melamine-encapsulated APP (eAPP). Using LW from tanneries as adjuvants to enhance P-FRs in EVA reduces industrial wastes that otherwise require costly waste management solutions. Materials are characterized multi-methodically via mechanical tests, electron microscopy, rheology, thermogravimetric analysis, evolved gas analysis, and condensed phase FTIR, also reaction-to-small-flames and cone calorimeter tests. EVA containing 10 wt-% LW and 20 wt-% P-FRs achieve 20% reductions in fire loads versus EVA, and up to 10% reduction in effective heats of combustion versus EVA with equal (30 wt-%) P-FR loadings. Enhanced char stabilization of EVA composites with LW and P-FRs lowered peaks of heat release rates up to 53% compared to EVA, and up to 40% compared to equal P-FRs loadings. Synergisms between LW and P-FRs in EVA are quantified. A chemical decomposition mechanism is proposed. KW - Leather waste KW - Tannery industry KW - EVA KW - Fire protection KW - Flame retardancy KW - Charring PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532977 DO - https://doi.org/10.1016/j.matdes.2021.110100 SN - 0264-1275 VL - 210 SP - 1 EP - 16 PB - Elsevier CY - Amsterdam AN - OPUS4-53297 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 - JOUR A1 - Battig, Alexander A1 - Müller, Patrick A1 - Bertin, Annabelle A1 - Schartel, Bernhard T1 - Hyperbranched Rigid Aromatic Phosphorus-Containing Flame Retardants for Epoxy Resins N2 - A rigid aromatic phosphorus-containing hyperbranched flame retardant structure is synthesized from 10-(2,5 dihydroxyphenyl)-10H-9-oxa- 10-phosphaphenanthrene-10-oxide (DOPO-HQ), tris(4-hydroxyphenyl)phosphine oxide (THPPO), and 1,4-terephthaloyl chloride (TPC). The resulting poly-(DOPO-HQ/THPPO-terephthalate) (PDTT) is implemented as a flame retardant into an epoxy resin (EP) at a 10 wt% loading. The effects on EP are compared with those of the monomer DOPO-HQ and triphenylphosphine oxide (OPPh3) as low molar mass flame retardants. The glass transition temperature, thermal decomposition, flammability (reaction to small flame), and burning behavior of the thermosets are investigated using differential scanning calorimetry, thermogravimetric analysis, pyrolysis combustion flow calorimetry, UL 94-burning chamber testing, and cone calorimeter measurements. Although P-contents are low at only 0.6 wt%, the study aims not at attaining V-0, but at presenting a proof of principle: Epoxy resinswith PDTT show promising fire performance, exhibiting a 25% reduction in total heat evolved (THE), a 30% reduction in peak heat release rate (PHRR) due to flame inhibition (21% reduction in effective heat of combustion (EHC)), and an increase in Tg at the same time. This study indicates that rigid aromatic hyperbranched polymeric structures offer a promising route toward multifunctional flame retardancy. KW - Hyperbranched KW - Aromatic KW - Phosphorus KW - Phosphine oxide KW - DOPO KW - Flame retardant KW - Xpoxy resin KW - Rigid PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-525910 DO - https://doi.org/10.1002/mame.202000731 SN - 1439-2054 VL - 306 IS - 4 SP - 731 PB - Wiley AN - OPUS4-52591 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -