TY - JOUR A1 - Shabir Mahr, Muhammad A1 - Hübert, Thomas A1 - Sabel, Martin A1 - Schartel, Bernhard A1 - Bahr, Horst A1 - Militz, H. T1 - Fire retardancy of sol-gel derived titania wood-inorganic composites N2 - Sol–gel technology was applied in tailoring novel wood-made-inorganic composites with improved thermal and fire properties. In practice, composites materials were prepared by impregnating pine sapwood wood with nano-scaled precursor solutions derived from titanium(IV) isopropoxide followed by a thermal curing process. Thermal and fire properties were evaluated by thermal analysis and cone calorimetry, whereas flammability was specified by oxygen index (LOI) and UL 94 test. Peak heat release rates were moderately reduced indicating fire retardance potential in terms of flame spread attributed to the appropriate protection layer action of the titania-based depositions. LOI (oxygen index) values of these composites were increased up to 38 vol.% in comparison to 23 vol.% for untreated wood. The flame retardancy performance depends on the fire scenario and is strongly influenced by wood loading and crackfree deposition of the titania layers inside the composite. PY - 2012 DO - https://doi.org/10.1007/s10853-012-6628-3 SN - 0022-2461 SN - 1573-4803 VL - 47 IS - 19 SP - 6849 EP - 6861 PB - Springer Science + Business Media B.V. CY - Norwell, Mass. AN - OPUS4-26235 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shabir Mahr, Muhammad A1 - Hübert, Thomas A1 - Schartel, Bernhard A1 - Bahr, Horst A1 - Sabel, Martin A1 - Militz, H. T1 - Fire retardancy effects in single and double layered sol-gel derived TiO2 and SiO2-wood composites N2 - Sol–gel derived TiO2 and SiO2-wood inorganic composites are prepared by direct vacuum infiltration of silicon and titanium alkoxide based precursors in pine sapwood in one or two cycles followed by a controlled thermal curing process. The resulting flame retardancy effect is investigated under two different fire scenarios using cone calorimetry and oxygen index (LOI). Heat release rates (HRR) especially the values for the second peak, are reduced moderately for all single layered composites. This effect is more pronounced for double layered composites where HRR was reduced up to 40 % showing flame retardancy potential in developing fires. Beside this, smoke release was lowered up to 72 % indicating that these systems had less fire hazards compared to untreated wood, whereas no meaningful improvement is realized in terms of fire load (total heat evolved) and initial HRR increase. However impressively, the LOI of the composites were increased up to 41 vol% in comparison to 23 vol% for untreated wood displaying a remarkable flame retardancy against reaction to a small flame. An approximate linear interdependence among the fire properties and the material loading as well as fire residue was observed. A residual protection layer mechanism is proposed improving the residue properties for the investigated composites. KW - Wood KW - Sol-gel KW - Composite materials KW - Cone calorimeter KW - Fire retardance KW - Flammability PY - 2012 DO - https://doi.org/10.1007/s10971-012-2877-5 SN - 0928-0707 SN - 1573-4846 VL - 64 IS - 2 SP - 452 EP - 464 PB - Kluwer Academic Publ. CY - Dordrecht AN - OPUS4-27618 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chacon Castro, Jose P. A1 - Schartel, Bernhard T1 - Translating Flame Retardant Strategies: Analogy from Polyolefins and Bisphenol A polycarbonates to Poly(limonene carbonate) N2 - Poly(limonene carbonate)—PLimC—offers a novel sustainable alternative to traditional polymers, as it is derived from renewable limonene and carbon dioxide as monomers. Proposing PLimC as a future technical polymer for applications in electrical and electronic (E&E) devices, construction, and transportation, PLimC must meet specific fire prevention standards to be deemed suitable. Starting from the chemical structure of PLimC, strategies in analogy to flame retarded bisphenol A polycarbonates (PC), PC blends, and polyolefins (PO) are investigated to identify the most effective route to enhance the flame resistance of PLimC. This study utilized four halogen-free flame-retardant (FR) systems: APP + pentaerythritol (standard intumescent system in PO), a phosphorus flame retardant+PTFE as anti-dripping agent (used in PC blends), metal hydroxide ATH (widely used in PO), and potassium sulfonate salt (specific solution for PC). Applying these FRs at typical PC, PC blends, and PO loadings, we aim to understand their effect on PLimC and evaluated the different flame-retardant routes. Our experimental evaluations focused on the thermal properties, flammability, and fire behavior of each system. ATH emerged as the most effective, reducing the effective heat of combustion from 29.3 MJ kg⁻¹ to 18.6 MJ kg⁻¹ and the total heat evolved from 95 to 55 MJ m⁻². It also resulted in an increase in the limiting oxygen index from 17.1 to 26 vol.-% O2, along with a UL 94 HB40 rating. The intumescent system also exhibited considerable flame retardancy, highlighting the similarity of PLimC’s fire behavior to that of PO rather than PC KW - Poly(limonene carbonate) KW - Flame retardancy KW - Sustainability KW - Intumescent systems KW - Metal hydroxides KW - Sulfonate salts KW - Phosphorus flame retardants PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643257 DO - https://doi.org/10.1016/j.polymdegradstab.2025.111711 SN - 1873-2321 SN - 0141-3910 VL - 242 SP - 1 EP - 18 PB - Elsevier Ltd. AN - OPUS4-64325 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Frasca, Daniele A1 - Schulze, Dietmar A1 - Wachtendorf, Volker A1 - Krafft, Bernd A1 - Rybak, Thomas A1 - Schartel, Bernhard T1 - Multilayer Graphene/Carbon Black/Chlorine Isobutyl Isoprene Rubber Nanocomposites N2 - High loadings of carbon black (CB) are usually used to achieve the properties demanded of rubber compounds. In recent years, distinct nanoparticles have been investigated to replace CB in whole or in part, in order to reduce the necessary filler content or to improve performance. Multilayer graphene (MLG) is a nanoparticle made of just 10 graphene sheets and has recently become commercially available for mass-product nanocomposites. Three phr (part for hundred rubbers) of MLG are added to chlorine isobutyl isoprene rubber (CIIR)/CB composites in order to replace part of the CB. The incorporation of just 3 phr MLG triples the Young’s modulus of CIIR; the same effect is obtained with 20 phr CB. The simultaneous presence of three MLG and CB also delivers remarkable properties, e.g. adding three MLG and 20 phr CB increased the hardness as much as adding 40 phr CB. A comprehensive study is presented, showing the influence on a variety of mechanical properties. The potential of the MLG/CB combination is illustrated to reduce the filler content or to boost performance, respectively. Apart from the remarkable mechanical properties, the CIIR/CB/MLG nanocomposites showed an increase in weathering resistance. KW - nanocomposites KW - rubber KW - multilayer graphene KW - carbon black PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-358569 DO - https://doi.org/10.3390/polym8030095 SN - 2073-4360 VL - 8 SP - 95 PB - MDPI CY - Basel, Switzerland AN - OPUS4-35856 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kempel, Florian A1 - Schartel, Bernhard A1 - Linteris, G.T. A1 - Stoliarov, S.I. A1 - Lyon, R.E. A1 - Walters, R.N. A1 - Hofmann-Böllinghaus, Anja T1 - Prediction of the mass loss rate of polymer materials: Impact of residue formation N2 - Two different numerical simulation tools, Fire Dynamic Simulator (FDS) and ThermaKin, are investigated with respect to their capability to predict the mass loss rate of polymer materials exposed to different fires. For validation, gasification apparatus and cone calorimeter tests are conducted. The main focus is on the influence of residue formation. Therefore, poly (butylene terephthalate) (PBT) and PBT reinforced with glass fibres (PBT-GF) are investigated and compared. PBT decomposes almost completely, while PBT-GF forms residue. The materials are characterised in order to provide suitable input parameters. Additionally the total incident heat flux to the sample is measured. With accurate input parameters, FDS and ThermaKin predicted the pyrolysis behaviour of PBT very well. Only some limitations are identified regarding the residue-forming PBT-GF. Both numerical simulation tools demonstrate a high value regarding the assessment of parameters' relative impacts and thus the evaluation of optimisation routes in polymer and composite development. KW - Polymer KW - Pyrolysis simulation KW - Residue formation KW - Fire dynamics simulator (FDS) KW - ThermKin PY - 2012 DO - https://doi.org/10.1016/j.combustflame.2012.03.012 SN - 0010-2180 SN - 1556-2921 VL - 159 IS - 9 SP - 2974 EP - 2984 PB - Elsevier CY - New York, NY AN - OPUS4-26382 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Morys, Michael A1 - Illerhaus, Bernhard A1 - Sturm, Heinz A1 - Schartel, Bernhard T1 - Revealing the inner secrets of intumescence: Advanced standard time temperature oven (STT Mufu+)—my‐computed tomography approach N2 - Intumescent coatings have been used for fire protection of steel for decades, but there is still a need for improvement and adaptation. The key parameters of such coatings in a fire Scenario are thermal insulation, foaming dynamics, and cohesion. The fire resistance tests, large furnaces applying the standard time temperature (STT) curve, demand coated full‐scale components or intermediate‐scale specimen. The STT Mufu+ (standard time temperature muffle furnace+) approach is presented. It is a recently developed bench‐scale testing method to analyze the performance of intumescent coatings. The STT Mufu+ provides vertical testing of specimens with reduced specimen size according to the STT curve. During the experiment, the foaming process is observed with a high‐temperature endoscope. Characteristics of this technique like reproducibility and resolution are presented and discussed. The STT Mufu+ test is highly efficient in comparison to common tests because of the reduced sample size. Its potential is extended to a superior research tool by combining it with advanced residue analysis (μ‐computed tomography and scanning electron microscopy) and mechanical testing. The benefits of this combination are demonstrated by a case study on 4 intumescent coatings. The evaluation of all collected data is used to create performance‐based rankings of the tested coatings. KW - Bench‐scale fire testing KW - Computed tomography KW - Fire resistance KW - Intumescence KW - Residue analysis KW - Standard time temperature furnace PY - 2017 DO - https://doi.org/10.1002/fam.2426 SN - 0308-0501 SN - 1099-1018 VL - 41 IS - 8 SP - 927 EP - 939 PB - Wiley AN - OPUS4-42754 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Morys, Michael A1 - Illerhaus, Bernhard A1 - Sturm, Heinz A1 - Schartel, Bernhard T1 - Variation of intumescent coatings revealing different modes of action for good protection performance N2 - Thermal insulation and mechanical resistance play a crucial role for the performance of an intumescent coating. Both properties depend strongly on the morphology and morphological development of the foamed residue. Small amounts (4 wt%) of fiberglass, clay and a copper salt, respectively, are incorporated into an intumescent coating to study their influence on the morphology and Performance of the residues. The bench scale fire tests were performed on 75 x 75 x 2 mm³ coated steel plates according to the standard time–temperature curve in the Standard Time Temperature Muffle Furnace+ (STT Mufu+). It provided information about foaming dynamics (expansion rates) and thermal insulation. Adding the copper salt halved the expansion height, whereas the clay and fiberglass Change the height of the residue only moderately. The time to reach 500 °C was improved by 31% for clay and 15% for the other two fillers. Nondestructive micro computed tomography is used to assess the inner structure of the residues. A transition of the residue from a black, carbonaceous foam with closed cells into an inorganic, residual open cell sponge occurs at high temperatures. This transition is due to a loss of carbon; the change in microstructure is analyzed by scanning electron microscopy. Additional mechanical tests are performed and interpreted with respect to the results of the morphology analysis. Adding clay or copper salt improved the mechanical resistance tested by a factor 4. The additives significantly influence the thickness and foaming Dynamics as well as the inner structure of the residues, whereas their influence on insulation Performance is moderate. In conclusion, different modes of action are observed to achieve similar insulation performance during the fire test. KW - Intumescence KW - Coating KW - Bench scale fire testing KW - Computed tomography KW - Fire resistance PY - 2017 DO - https://doi.org/10.1007/s10694-017-0649-z SN - 0015-2684 SN - 1572-8099 VL - 53 IS - 4 SP - 1569 EP - 1587 PB - Springer AN - OPUS4-40751 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Morys, Michael A1 - Illerhaus, Bernhard A1 - Sturm, Heinz A1 - Schartel, Bernhard T1 - Size is not all that matters: Residue thickness and protection performance of intumescent coatings made from different binders N2 - In addition to the acid source, charring agent, and blowing agent, the binder is a crucial part of an intumescent coating. Its primary task is to bind all compounds, but it also acts as a carbon source and influences the foaming process. A series of intumescent coatings based on five different binders was investigated in terms of insulation, foaming, mechanical impact resistance, and residue morphology. The Standard Time-Temperature modified Muffle Furnace (STT MuFu+ ) was used for the bench-scale fire resistance tests and provided data on temperature and residue thickness as well as well-defined residues. The residue morphology was analyzed by nondestructive m-computed tomography and scanning electron microscopy. A moderate influence of the binder on insulation performance was detected in the set of coatings investigated, whereas the foaming dynamics and thickness achieved were affected strongly. In addition, the inner structure of the residues showed a rich variety. High expansion alone did not guarantee good insulation. Furthermore, attention was paid to the relation between the microstructure transition induced by carbon loss due to thermo-oxidation of the char and the development of the thermal conductivity and thickness of the coatings during the fire test. KW - Intumescence KW - Morphology analysis KW - Computed tomography KW - Fire resistance KW - Bench-scale fire test KW - Fire protective coating PY - 2017 DO - https://doi.org/10.1177/0734904117709479 SN - 0734-9041 SN - 1530-8049 VL - 35 IS - 4 SP - 284 EP - 302 PB - Sage AN - OPUS4-40766 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Braun, Ulrike A1 - Bahr, Horst A1 - Sturm, Heinz A1 - Schartel, Bernhard T1 - Flame retardancy mechanisms of metal phosphinates and metal phosphinates in combination with melamine cyanurate in glass-fiber reinforced poly(1,4-butylene terephthalate): the influence of metal cation N2 - The pyrolysis and fire behavior of glass-fiber reinforced poly(butylene terephthalate) (PBT/GF) with two different metal phosphinates as flame retardants in combination with and without melamine cyanurate (MC) were analyzed by means of thermogravimetry, thermogravimetry coupled with infrared spectroscopy, flammability, and cone calorimeter tests as well as scanning electron microscopy/energy dispersive X-ray spectroscopy and X-ray fluorescence spectroscopy. In PBT/GF, dosages of 13-20% of the halogen-free flame retardant aluminum phosphinate or aluminum phosphinate in combination with MC fulfill the requirements for electrical engineering and electronics applications (UL 94 = V-0; LOI > 42%), whereas the use of the same amount of zinc phosphinate or zinc phosphinate in combination with MC does not improve the fire behavior satisfactorily (UL 94 = HB; LOI = 27-28%). The performance under forced flaming conditions (cone calorimeter) is quite similar for both of the metal phosphinates. The use of aluminum and zinc salts results in similar flame inhibition predominantly due to the release of the phosphinate compounds in the gas phase. Both metal phosphinates and MC interact with the polymer changing the decomposition characteristics. However, part of the zinc phosphinate vaporizes as a complete molecule. Because of the different decomposition behavior of the metal salts, only the aluminum phosphinate results in a small amount of thermally stable carbonaceous char. In particular, the aluminum phosphinate-terephthalate formed is more stable than the zinc phosphinate-terephthalate. The small amount of char has a crucial effect on the thermal properties and mechanical stability of the residue and thus the flammability. KW - Flame retardance KW - Polyester KW - Phosphinates KW - Pyrolysis KW - Cone calorimeter PY - 2008 DO - https://doi.org/10.1002/pat.1147 SN - 1042-7147 SN - 1099-1581 VL - 19 IS - 6 SP - 680 EP - 692 PB - John Wiley & Sons, Ltd. CY - Chichester AN - OPUS4-17620 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Weiß, André A1 - Sturm, Heinz A1 - Kleemeier, M. A1 - Hartwig, A. A1 - Vogt, C. A1 - Fischer, R.X. T1 - Layered silicate epoxy nanocomposites: formation of the inorganic-carbonaceous fire protection layer N2 - The layered silicate (LS) modification and processing parameters applied control the morphology of the LS/polymer composites. Here, increasing the surface area of the LS particles by using alternative drying processes increases dispersion towards a more typical nanocomposite morphology, which is a basic requirement for promising flame retardancy. Nevertheless, the morphology at room temperature does not act itself with respect to flame retardancy, but serves as a prerequisite for the formation of an efficient surface protection layer during pyrolysis. The formation of this residue layer was addressed experimentally for the actual pyrolysis region of a burning nanocomposite and thus our results are valid without any assumptions or compromises on the time period, dimension, surrounding atmosphere or temperature. The formation of the inorganic-carbonaceous residue is influenced by bubbling, migration, reorientation, agglomeration, ablation, and perhaps also delamination induced thermally and by decomposition, whereas true sintering of the inorganic particles was ruled out as an important mechanism. Multiple, quite different mechanisms are relevant during the formation of the residue, and the importance of each mechanism probably differs from one nanocomposite system to another. The main fire protection effect of the surface layer in polymer nanocomposites based on non-charring or nearly non-charring polymers is the increase in surface temperature, resulting in a substantial increase in reradiated heat flux (heat shielding). KW - Nanocomposite KW - Fire retardancy KW - Epoxy resin KW - Fire behavior KW - Flammability PY - 2011 DO - https://doi.org/10.1002/pat.1644 SN - 1042-7147 SN - 1099-1581 VL - 22 IS - 12 SP - 1581 EP - 1592 PB - John Wiley & Sons, Ltd. CY - Chichester AN - OPUS4-24916 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -