TY - CONF A1 - Böhning, Martin A1 - Tidjani, Adams A1 - Wald, Oliver A1 - Turky, Gamal A1 - Goering, Harald A1 - Brzezinka, Klaus-Werner A1 - Schartel, Bernhard A1 - Schönhals, Andreas T1 - Polypropylene/Clay Nanocomposites - Gas Transport Characteristics and Molecular Mobility T2 - Polydays 2002 CY - Berlin, Germany DA - 2002-09-30 PY - 2002 SP - 1(?) EP - 2(?) AN - OPUS4-2038 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gallo, Emanuela A1 - Schartel, Bernhard A1 - Schmaucks, G. A1 - von der Ehe, Kerstin A1 - Böhning, Martin T1 - Effect of well dispersed amorphous silicon dioxide in flame retarded styrene butadiene rubber N2 - Spherically shaped amorphous silicon dioxide with broad size particle distribution was used in combination with aluminium trihydroxide (ATH) in styrene butadiene rubber composites. The pyrolysis, flammability, fire properties, flame spread and gas diffusion were investigated. The kind and amount of ATH, but in particular the fine silicon dioxide chosen as an additive, influenced the thermal decomposition and fire behaviour of styrene butadiene rubber composites. Gravimetric gas sorption measurements showed that the gas diffusion was systematically lower with silicon dioxide. The initial pyrolysis gas release was hindered, increasing the temperature at which decomposition begins as well as the ignition time in fire tests. During combustion, ATH and silicon dioxide accumulate on the surface of the specimen, forming a residual protective layer. A reduced peak heat release rate and fire spread were observed. The addition of a special kind of silicon dioxide is proposed to play a key role in optimising fire retardancy. KW - Flame retardancy KW - Styrene butadiene rubber KW - SBR KW - Silicon dioxide KW - Aluminium trihydroxide KW - ATH PY - 2013 DO - https://doi.org/10.1179/1743289812Y.0000000012 SN - 1465-8011 SN - 1743-2898 VL - 42 IS - 1 SP - 34 EP - 42 PB - IOM Communications CY - London, UK AN - OPUS4-27626 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Frasca, Daniele A1 - Schulze, Dietmar A1 - Böhning, Martin A1 - Krafft, Bernd A1 - Schartel, Bernhard T1 - Chlorbutylkautschuk/Multilayergraphen-Nanocomposites N2 - In den letzten Jahren werden zunehmend Nanopartikel als Füllstoff für Polymere vorgeschlagen und auch erfolgreich in Elastomer-Nanocomposites eingesetzt. In dieser Arbeit wird Multilayergraphen (MLG) als Nanofüllstoff näher untersucht, der sich bereits bei geringen Konzentrationen als effizient erweist. MLG besteht aus nur etwa zehn Graphenlagen. Chlorbutylkautschuk (CIIR)/MLG-Nanocomposites mit verschiedenen MLG-Gehalten wurden mit Hilfe eines ultraschallunterstützen Mischverfahrens in Lösung hergestellt und auf einem Walzwerk weiterverarbeitet. Das Einmischen von MLG führt zu einer deutlichen Verbesserung der rheologischen und mechanischen Eigenschaften, des Vernetzungsverhaltens sowie der Barrierewirkung gegenüber Gasen. Bereits der Zusatz von 3 phr MLG zu CIIR führt zu einem mehr als zweifach höheren E-Modul und zu einer Reduktion der Permeabilität von O2 und CO2 um 30 %. Höhere Konzentrationen an Nanofüllstoff resultieren in einer weiteren Verbesserung der Eigenschaften der Nanocomposites. Weiterhin zeigten die CIIR/MLG-Nanocomposites auch eine geringere Entflammbarkeit. KW - Elastomere KW - Nanokomposite KW - Graphen KW - Chlorbutylkautschuk PY - 2017 SN - 0176-1625 VL - 70 IS - 5 SP - 311 EP - 322 PB - Dr. Gupta Verlag CY - Ratingen AN - OPUS4-40327 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schartel, Bernhard T1 - Flame Retardancy Features Sustainability Food for Thought, Fake Fiction, and Future N2 - Sustainability (environmental conservation for the economic welfare and prosperity for all) would revolutionise the plastics industry were it to become predominant practice as a linear, fossil-fuel–based economy is switched to a carbon circular one. Hence, the innovative field of flame-retardant polymeric materials should lend its strength to drive this challenge. Visionary solutions are proposed to inspire us, while the implementation of economically feasible concepts take us forward into the future. A critical overview of current trends is presented, using examples from the literature and our own recent projects. The examples lead from the use of natural materials with some intrinsic flame retardancy, via biocomposites, to using renewable sources for flame retardants. Natural flame retardants and adjuvants are highlighted, motivating our vision. Some of the visionary approaches such as flame-retardant poly(limonene carbonate) or wastewater phosphorus enriched micro algae as a sustainable flame retardant are rather innovative. Further, natural material streams find their way into polymer mass production as fillers, adjuvants, or renewable educt sources; industrial waste streams open the door to sustainable solutions, because they avoid competition for land with farming or virgin forests. Remarks will address recycling, flame retardant vitrimers are potential materials for recyclable thermosets. Only convincing property profiles will prevail both for exploiting renewable sources and circular design; sustainability must not be merely tolerated as an additional demand but should instead be recognized as a solution ensuring our economic welfare now and in the future. Acknowledgement: Funding: BMBF WTZ 01DN16040, DFG Scha 730/19 u. 20, VW-Stiftung: Experiment 97437, BMBF KMU Innovativ 031B1289B. People: A Battig, R Bhatia, J Chacon Castro, M Dudziak, SF Falkenhagen, FR Gleuwitz, a.o. (BAM) and G Sánchez Olivares (CIATEC), R Dey (Constructor University), A Greiner (Bayreuth), a.o. T2 - 19th Bayreuth Polymer Symposium CY - Bayreuth, Germany DA - 21.09.2025 KW - Poly(limonene carbonate) KW - Flame retardant biocomposites KW - Wastewater phosphorus enriched micro algae KW - Non-vegan flame retardant KW - Flame retardant vitrimers KW - Bio-based flame retardant PY - 2025 AN - OPUS4-64204 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sut, Aleksandra A1 - Greiser, Sebastian A1 - Jäger, Christian A1 - Schartel, Bernhard T1 - Interactions in multicomponent flame-retardant polymers: Solid-state NMR identifying the chemistry behind it N2 - Distinct approaches are used to reduce the fire risks of polymers, a key issue for many industrial applications. Among the variety of approaches, the use of synergy in halogen-free multicomponent systems is one of the most auspicious. To optimize the composition of such flame-retardant systems it is essential to understand the mechanisms and the corresponding chemistry in the condensed phase. In this work different methods are used, including cone calorimeter, thermogravimetry (TG), and TG-FTIR, with the main focus on the solid-state NMR analysis of the solid residues. The structural changes in the condensed phase of two thermoplastic elastomer systems based on copolymer styrene-ethylene-butadiene-styrene (TPE-S) were investigated: TPE-S/aluminium diethylphosphinate (AlPi)/magnesium hydroxide (MH) and TPE-S/AlPi/zinc borate (ZB)/poly(phenylene oxide) (PPO). Strong flame inhibition is synergistically combined with protective layer formation. 13C-, 27Al-, 11B- and 31P MAS NMR (magic angle spinning nuclear magnetic resonance) experiments using direct excitation with a single pulse and 1H–31P cross-polarization (CP) were carried out as well as double resonance techniques. Magnesium phosphates were formed during the pyrolysis of TPE-S/AlPi/MH, while for the system TPE-S/AlPi/ZB/PPO zinc phosphates and borophosphates were observed. Thus, the chemistry behind the chemical interaction was characterized unambiguously for the investigated systems. KW - Synergy KW - Solid-state NMR KW - Flame retardancy KW - SEBS KW - Aluminium diethylphosphinate KW - Magnesium hydroxide KW - Zinc borate KW - Poly(phenylene) oxide PY - 2015 DO - https://doi.org/10.1016/j.polymdegradstab.2015.08.018 SN - 0141-3910 SN - 1873-2321 VL - 121 SP - 116 EP - 125 PB - Applied Science Publ. CY - London AN - OPUS4-34306 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rockel, Daniel A1 - Sanchez Olivares, G. A1 - Calderas, F. A1 - Schartel, Bernhard T1 - It’s not waste, it’s a resource: Utilizing industrial waste fibers/mineral fillers to attain flame retardant biocomposites N2 - Integrating natural fibers derived from local industrial waste streams into thermoplastic starch (TPS) proves to be a promising approach towards sustainable flame retardant biocomposites. Initially, three types of waste fibers from the agave, coconut, and leather industries were evaluated for their flame retardant properties in combination with aluminum trihydroxide (ATH), an environmental friendly flame retardant. Leather fiber (BLF) exhibited the best flame retardant performance and were further investigated along with ATH and varying amounts of bentonite nanoclay to enhance the residual protective layer. The combination of multiple components shows improvement in performance while reducing the total load of filler. The images of the fire residues revealed that a more enclosed surface correlates with a reduction in the peak of heat release rate. Whereas higher amounts of bentonite does not deliver further inprovements, only 1 phr nanoclay in the novel multicomponent system of TPS, ATH, BLF, and bentonite synergistically improved the UL-94 rating from HB to V1. The proposed system brings together the different approaches using a renewable biopolymer, natural waste fibres, and envirnmentally friendly flame retardancy and thus, is striking for its combination of outstanding sustainablity, instant feasability, and sufficient fire performance. KW - Biocomposites KW - Flame retardancy KW - Residue analysis KW - Sustainability KW - Waste streams PY - 2025 DO - https://doi.org/10.1177/08927057241297083 SN - 0892-7057 SN - 1530-7980 VL - 38 IS - 6 SP - 2225 EP - 2252 PB - Sage AN - OPUS4-63431 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sunder, S. A1 - Jauregui Rozo, Maria A1 - Inasu, S. A1 - Meinel, Dietmar A1 - Schartel, Bernhard A1 - Ruckdäschel, H. T1 - Effect of Ammonium Polyphosphate/Silicate Content on the Postfire Mechanics of Epoxy Glass-Fiber Composites Using Facile Chocolate Bar-Inspired Structures N2 - This study investigates the postfire mechanical properties of epoxy glass-fiber reinforced composites (EP GFRCs) using increasing concentrations of ammonium polyphosphate (APP) and inorganic silicate (InSi) to modify the char and fire residue. A facile chocolate bar-inspired structure was introduced for fire exposure and subsequent flexural testing of the GFRCs. The resin matrix used here was a diglycidyl ether of bisphenol-A (DGEBA) resin, cured with dicyandiamide (DICY), and accelerated by Urone. The microstructures of the degraded composites after three-point bending tests, were evaluated using scanning electron microscopy (SEM) and x-ray computed tomography (XCT) imaging. A previous study showed that increasing the APP and InSi content significantly enhanced flame retardancy, via improved char formation under fire conditions. However, flexural properties and fire resistance were adversely affected after fire exposure, highlighting a trade-off effect. Fiber breakage and delamination of the composites increased upon failure with increasing APP + InSi content in the composite due to unconsolidated char. The experimental values for the postfire flexural mechanics were in good agreement with the two-layer model proposed in literature. This paper presents a preliminary basis for postfire mechanical testing of epoxy composites for use in fire-safe structures, using a combination of standardized testing norms. KW - Flame retardants KW - Post-fire KW - Epoxy KW - Gass fiber composites KW - Prepregs PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-627176 DO - https://doi.org/10.1002/fam.3280 SN - 0308-0501 SN - 1099-1018 VL - 49 IS - 3 SP - 329 EP - 346 PB - Wiley AN - OPUS4-62717 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bibinger, J. A1 - Eibl, S. A1 - Gudladt, H.-J. A1 - Schartel, Bernhard A1 - Höfer, P. T1 - Pushing the limits of thermal resistance in nanocomposites: A comparative study of carbon black and nanotube modifications N2 - Enhancing the thermal resistance of carbon fiber-reinforced polymers (CFRPs) with flame retardants or coatings often leads to increased weight and reduced mechanical integrity. To address these challenges, this study introduces an innovative approach for developing nanocomposites using carbon-based nanoparticles, while preserving the structural lightweight properties. For this, carbon black particles (CBPs) up to 10% and carbon nanotubes (CNTs) up to 1.5% were incorporated into the RTM6/G939 composite material. The obtained samples were then analyzed for their properties and heat resistance under one-sided thermal loading at a heat flux of 50 kW/m2. Results demonstrate that integrating these particles improves heat conduction without compromising the material’s inherent advantages. As a result, thermo-induced damage and the resulting loss of mechanical strength are delayed by 17% with CBPs and 7% with CNTs compared to the unmodified material. Thereby, the thermal behavior can be accurately modeled by a straightforward approach, using calibrated, effective measurements of the nanoparticles in the polymer matrix rather than relying on theoretical assumptions. This approach thus provides a promising methode to characterize and improve thermal resistance without significant trade-offs. KW - Nanomaterial KW - Cabon fiber-reinforced polymer (CFRP) KW - Carbon black (CB) KW - Carbon nanotube (CNT) KW - Improving heat conduction KW - Prediction thermal properties PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-628632 DO - https://doi.org/10.3390/nano15070546 SN - 2079-4991 VL - 15 IS - 7 SP - 1 EP - 23 PB - MDPI CY - Basel AN - OPUS4-62863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hupp, Vitus A1 - Schartel, Bernhard A1 - Flothmeier, K. A1 - Hartwig, A. T1 - Flame Retarded Adhesive Tapes and Their Influence on the Fire Behavior of Bonded Parts N2 - Pressure-sensitive adhesive tapes are used in automotives, railway vehicles and construction, where flame retardancy is of major importance. This is why industrial applicants often buy, and industrial tape manufacturers often produce, flame-retardant adhesive tapes, advertised for their good flammability characteristics. Yet, how flame-retardant tapes influence the fire behavior of bonded materials is a rather open question. To investigate this issue, three different substrates were bonded, using eight double-sided adhesive tapes containing two different carriers and two different flame retardants. The bonded substrates were compared to their monolithic counterparts in terms of flammability, fire behavior and fire stability. The fire behavior of adhesive tape bonded materials differed significantly from the monolithic substrates. The usage of different adhesive tapes let to different burning behavior of the bonded materials mainly due to different carrier systems. In contrast, the implementation of flame retardant into the adhesive had rather minor or no effect on the burning behavior of the bonded substrates despite their positive effect on the flammability of the free-standing tape. The carrier changed the HRR curve in the cone calorimeter and was able to both, reduce and increase fire hazards. Using the carrier with the better fire performance can lower the fire growth rate by 20%, the peak of heat release rate by 27%, and the maximum average rate of heat emission by 30% in cone calorimeter tests. Overall, the fire behavior of bonded materials is a complex interaction between substrate, adhesive, and carrier, and depends on the fire scenario the materials are exposed to. KW - Pressure-sensitive adhesive tapes KW - Bonded materials KW - Fire behaviour KW - Fire resistance KW - Flame retardant KW - Cone calorimeter PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-626006 DO - https://doi.org/10.1007/s10694-024-01637-2 SN - 1572-8099 SN - 0015-2684 VL - 61 IS - 2 SP - 729 EP - 749 PB - Springer Nature AN - OPUS4-62600 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schartel, Bernhard T1 - 1 + 1 ≠ 2 – Laminate Materials Meet Flame Retardancy N2 - Main message: Fire tests monitor the specific response of defined test specimens but are used to assess materials’ fire risks. The weakness of this simplification becomes obvious for laminate materials. The talk delivers inspiring food for thought in discussing the fire behaviour of laminates. The fire behaviour must not be expected to be a simple superposition. The design of laminate can generate fire risks as well as give birth to flame retardancy. Introduction Bench-scale fire testing monitors the reaction-to-fire response of well-defined test specimens in certain fire scenarios. Results are often discussed as kind of material properties; indeed, the fire risks of materials are assessed. The weakness of this simplifying concept becomes obvious when it comes to investigating material systems such as all kind of laminate materials. The talk delivers inspiring food for thought sketching the complex and sometimes surprising fire behaviour of laminates. Experimental The polymer analysis, thermal analysis, and investigation of fire behaviour were performed according to the state of the art, mostly in accordance with the ISO standards. We fulfil high quality standards in terms of maintenance, calibration, participation in round robins, and so on. Work steps such as compounding of the materials or injection moulding of test specimen were outsourced or done with partners that have the relevant core competence. The presentation is based on the conclusions and concrete results of projects performed in the group of the author, whose experimental is described in the corresponding scientific papers in detail.[1-3] Results and Discussion Examples show that the fire behaviour of laminates must not be expected to be a simple superposition of the fire behaviour of the individual materials. Indeed, laminate effects can be crucial and influence the flammability relevantly. The design of the laminate can generate fire risks as well as give birth to synergistic flame retardancy. Veneered wood, lacquered products, or foil laminated materials are sketched to illustrate the topic with its potential and challenges. Glued samples consisting of two plates of the same material are discussed to generate some basic understanding as well as to investigate the fire behaviour of glued materials. The impact of the glue line on the burning behaviour of different polymeric materials such as bisphenol A polycarbonate, polymethylmethacrylate, and wood differs remarkably.[2] Further, the role of the glue including but not limited to using flame retarded glues is scrutinized. Making the best out of this understanding we have proposed to concentrate flame retardancy in the top layer.[1, 3] To achieve optimum flame-retardant effect or flame retardancy without disturbing the property profile of the core, flame retardants are strategically concentrated in the surface layer of thermoplastic materials with a laminate structure. Several systems increasing the charring and forming a residual protective layer are identified showing a synergistic effect compared to homogenously flame retarded test specimen. This research presented a promising solution for reducing the use of flame retardants without sacrificing fire performance or mechanical properties, offering significant advantages for industrial applications. T2 - 20th European Meeting on Fire Retardant Polymeric Materials (FRPM2025) CY - Madrid, Spain DA - 03.06.2025 KW - Fire behaviour of laminates KW - Flame retardancy by laminate design PY - 2025 AN - OPUS4-63394 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schartel, Bernhard T1 - Fire Retardancy Featuring Sustainability: Food for Thought between Fake Fiction and Future N2 - MAIN MESSAGE: Sustainability, or in other words, exploiting environmental conservation for the economic welfare and prosperity for all, would revolutionise the plastics industry were it to become predominant practice as a linear, fossil-fuel–based economy is switched to a carbon circular economy. Food for though is given by dint of a critical overview of the current trends in sustainable flame-retardant polymeric materials. STARTING POINT AND INTRODUCTION: Transforming the plastics industry into a carbon circular economy over the next 30 years requires an immediate revolution entailing the development of cutting-edge materials and the planning of future industrial production plants. Hence, the innovative field of flame-retardant polymeric materials for electrical engineering, construction, or materials used in transportation should lend its strength to drive this challenge. Visionary solutions are proposed to inspire us, while the implementation of economically feasible concepts can take us forward into the future. A critical and structured overview of current trends towards sustainable, flame-retardant polymeric materials is presented, using examples from the literature and by sketching our own projects performed in recent years. RESULTS AND DISCUSSION: This overview of current trends towards producing sustainable, flame-retardant polymeric materials is presented, selecting outstanding and representative examples from the literature and sketching main points of our own projects performed in this field in recent years. The examples are structured along a common theme leading from the use of old and new natural materials with some intrinsic flame retardancy, via flame-retardant biopolymers and biocomposites, to using renewable sources for flame retardants with the objective of exploiting natural sources available as industrial waste streams. Natural flame retardants and adjuvants are highlighted, although the status of most may be assessed as merely motivating our vision. However, some of these visionary approaches such as discussing sustainable flame retardants for poly(limonene carbonate), a polymer synthesised from renewable waste and CO2, or wastewater phosphorus enriched micro algae as a sustainable flame retardant in polylactide are rather innovative when achieving a surprising high technological readiness level or providing a comprehensive solution for several urgent demands at once. Further, there are natural material streams finding their way into polymer mass production as fillers, adjuvants, polymers, or renewable educt sources. Natural substances originating from industrial waste streams open the door to sustainable solutions, because they are often available at low cost and avoid competition for land with farming or virgin forests. Aside from this main topic, remarks will address the recycling of flame-retarded polymeric materials; flame retardant vitrimers are mentioned as potential materials for recyclable thermosets. At the end of the day, only convincing property profiles will prevail both for exploiting renewable sources and circular design, including cost effectiveness, sufficient availability, consistent quality, processibility, mechanical properties, and flame retardancy. However, sustainability must not be merely tolerated as an additional demand, but should instead be recognized as a solution, because sustainability aspires to ensure our economic welfare now and in the future. T2 - Interflam 2025 CY - Royal Holloway, Egham, UK DA - 30.06.2025 KW - Biocomposites KW - Sustainability KW - Renewable KW - Bio wastefibres KW - Circular economy KW - Phosphorus flame retardants PY - 2025 AN - OPUS4-63671 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jauregui Rozo, Maria A1 - Sunder, S. A1 - Inasu, S. A1 - Meinel, Dietmar A1 - Ruckdäschel, H. A1 - Schartel, Bernhard T1 - Weaving Through Fire and Force: Fire Behavior and Fire Stability of Unidirectional, Bidirectional, and Woven Roving Glass-Fiber Composites N2 - This study systematically investigates the transfer of flame retardants (FRs) from epoxy resins to composites. The flame-retardant composites are formulated using bisphenol A diglycidyl ether as the resin and dicyandiamide as the hardener, reinforced with glass fibers (GFs) using various textile architectures: unidirectional (UD), bidirectional (BD), and woven rovings (WR). These composites are evaluated using bench-scale fire stability tests and cone calorimeter experiments to assess critical parameters, including the temperature at failure, time to failure, and fire behavior. Among the tested configurations, UD-GFs demonstrate superior flame retardancy, fire stability, flammability, and mechanical performance, attributed to their higher residue yield, forming a more efficient protective char layer. However, the addition of FRs is limited by their impact on the material's mechanical properties. When the FR content increases to 30 and 50 wt.% of the resin, the composites exhibit a decrease in mechanical performance, adversely affecting both time to failure and temperature at failure. While adding FRs reduces the risk of fire propagation, it does not substantially enhance fire stability or mechanical performance. KW - Fire Resistance KW - Fiber-Reinforced Polymer Composites KW - Fire Stability KW - Glass Fibers KW - Fire Behavior PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-631220 SN - 1438-7492 SN - 1439-2054 VL - 310 IS - 5 SP - 2400432 PB - Wiley VHC-Verlag AN - OPUS4-63122 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schartel, Bernhard T1 - Fire Retardancy Featuring Sustainability: Food for Thought between Fake Fiction and Future N2 - Sustainability, or in other words, exploiting resources under the terms of environmental conservation for the economic welfare and prosperity continuously over time, would revolutionise the plastics industry were it to become predominant practice as a linear, fossil-fuel–based economy is switched to a carbon circular economy. Food for though is given by dint of a critical overview of the current trends and mainly by sketching our own key projects performed in the field of sustainable flame-retardant polymeric materials in the recent years. T2 - Interflam 2025 CY - London, United Kingdom DA - 30.06.2025 KW - Biocomposites KW - Sustainability KW - Renewable KW - Bio wastefibres KW - Fire Behavior PY - 2025 VL - 1 SP - 187 EP - 190 PB - Interscience Communications Ltd AN - OPUS4-63681 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dey, R. A1 - Dudziak, Mateusz A1 - Prescher, A. A1 - Kreitsmann, T. A1 - Zhang, K. A1 - Posten, C. A1 - Thomson, C. A1 - Schartel, Bernhard A1 - Ullrich, M. S. A1 - Thomson, L. T1 - Sustainable Flame-Retardant Poly Lactic AcidBiocomposites Reinforced with Polyphosphate-EnrichedMicroalgae: Unlocking the Potential of Hyper-Compensation N2 - This study examines the dual benefits of microalgae cultivation for wastewatertreatment and the enhancement of polylactic acid-based biocomposites. UsingDesmodesmus sp. in a photobioreactor, both batch and continuous operationsachieve total nitrogen (TN) and total phosphorus (TP) removal rates of up to99.9%, maintaining TN and TP levels below 0.02 mg L−1 in the effluent, aligningwith European discharge standards. Continuous cultivation increases biomassproductivity from 0.102 to 0.43 g L−1 day−1 , a 322% improvement over batchoperations. Nutrient starvation followed by reintroduction to nutrient-richwastewater induces hyper-compensation luxury uptake, with P-enrichedcells accumulating 1.33% intracellular P within six hours — 21% higherthan natural accumulation. The results reveal that luxury phosphorus uptakein microalgae follows a triphasic system of uptake and storage, challengingthe previously suggested biphasic model. When incorporated into Poly lacticacid (PLA), the biomass enhances versatility, offering potential replacementof inorganic P in industrial applications, particularly flame retardants.Pyrolysis and cone calorimetry confirm the thermal and fire-retardantbenefits, with a 20% reduction in peak heat release rate and increased charyield. This work highlights microalgae’s role in sustainable biocomposites,supporting wastewater treatment, nutrient recovery, and CO2 sequestration. KW - biocomposites KW - biopolymers KW - Flame-retardant KW - Hyper compensation KW - Phycoremediation KW - Wastewater treatment PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-640408 DO - https://doi.org/10.1002/adsu.202500251 SN - 2366-7486 VL - 9 IS - 8 SP - 1 EP - 11 PB - Wiley VHC-Verlag AN - OPUS4-64040 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schartel, Bernhard T1 - Flammschutz von Faserverbundwerkstoffen: Grundlagen und Konzepte N2 - Vor allen Kurz- und Lang-Glasfaser-verstärkte, aber auch Carbonfaser verstärkte Faserverbundwerkstoffe werden in Schienenfahrzeugen eingesetzt. Dabei sind die Brandschutzanforderungen entsprechend EN 45545 zu erfüllen. Der Übersichtsvortrag führt in die Grundlagen des Brandverhaltens und des Flammschutzes von Compositen ein. Anhand von eigenen Arbeiten wird verdeutlicht, dass Flammschutz maßgeschneidert für Composite, die Matrix und für den zu bestehenden Brandtest erforderlich ist. T2 - SKZ Fachtagung Faserverbundwerkstoffe im Schienenfahrzeugbau CY - Merseburg, Germany DA - 14.05.2025 KW - Faserverbundwerkstoffe KW - Composite KW - Flammschutz KW - Brandverhalten PY - 2025 AN - OPUS4-63123 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schartel, Bernhard T1 - Rubber / Multilayer graphene nanocomposites N2 - Rubbers are usually reinforced with a high content (> 40 phr) of carbon black (CB) and silica. In recent years several nanofillers have been proposed, including expanded graphite/graphene. Extremely low loading of nanoparticles can considerably improve the properties. In this contribution multilayer graphene (MLG) is investigated as efficient nanofiller for rubbers. MLG has a BET specific surface area of 250 m2/g. Compared to a single graphene sheet, the MLG used constitutes only approximately 10 graphene sheets. When homogenously dispersed, it works at low loadings enabling the replacement of CB, increase in efficiency, or reduction in filler concentration. Actually the appropriate preparation yielded nanocomposites in which just 3 phr are sufficient to significantly improve the rheological, curing and mechanical properties of different rubbers, as shown for Chlorine-Isobutylene-Isoprene Rubber (CIIR), Nitrile-Butadiene Rubber (NBR), Natural Rubber (NR), and Styrene-Butadiene Rubber (SBR). A mere 3 phr of MLG tripled the Young’s modulus of CIIR, an effect equivalent to 20 phr of carbon black. Similar equivalents are observed for MLG/CB mixtures. MLG reduces gas permeability, increases thermal and electrical conductivities, and retards fire behavior. The higher the nanofiller concentration is (3 phr, 5 phr, and 10 phr was investigated), the greater the improvement in the properties of the nanocomposites. Moreover, the MLG nanocomposites improve stability of mechanical properties against weathering. An increase in UV-absorption as well as a pronounced radical scavenging are proposed and were proved experimentally. To sum up, MLG is interesting as multifunctional nanofiller and seems to be quite ready for rubber development. T2 - 9th International Conference on Modification, Degradation and Stabilization of Polymers, MoDeSt 2016 CY - Cracow, Poland DA - 04.09.2016 KW - Graphene KW - Nanocomposites KW - Rubber KW - Reinforcement KW - Weathering stability PY - 2016 AN - OPUS4-37378 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Strommer, Bettina A1 - Schulze, Dietmar A1 - Schartel, Bernhard A1 - Böhning, Martin T1 - Networking Skills: The Effect of Graphene on the Crosslinking of Natural Rubber Nanocomposites with Sulfur and Peroxide Systems N2 - Tailored crosslinking in elastomers is crucial for their technical applications. The incorporation of nanoparticles with high surface-to-volume ratios not only leads to the formation of physical networks and influences the ultimate performance of nanocomposites, but it also affects the chemical crosslinking reactions. The influence of few-layer graphene (FLG) on the crosslinking behavior of natural rubber is investigated. Four different curing systems, two sulfur-based with different accelerator-to-sulfur ratios, and two peroxide-based with different peroxide concentrations, are combined with different FLG contents. Using differential scanning calorimetry (DSC), vulcametry (MDR) and swelling measurements, the results show an accelerating effect of FLG on the kinetics of the sulfur-based curing systems, with an exothermic reaction peak in DSC shifted to lower temperatures and lower scorch and curing times in the MDR. While a higher accelerator-to-sulfur ratio in combination with FLG leads to reduced crosslinking densities, the peroxide crosslinkers are hardly affected by the presence of FLG. The good agreement of crosslink densities obtained from the swelling behavior confirms the suitability of vulcameter measurements for monitoring the complex vulcanization process of such nanocomposite systems in a simple and efficient way. The reinforcing effect of FLG shows the highest relative improvements in weakly crosslinked nanocomposites. KW - Nanocomposite KW - Elastomers KW - Graphene KW - Crosslinking KW - Network KW - Rubber KW - Vulcanization PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-560409 DO - https://doi.org/10.3390/polym14204363 VL - 14 IS - 20 PB - MDPI AN - OPUS4-56040 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Strommer, Bettina A1 - Schulze, Dietmar A1 - Schartel, Bernhard A1 - Böhning, Martin T1 - The quantification of anisotropy in graphene/natural rubber nanocomposites: Evaluation of the aspect ratio, concentration, and crosslinking N2 - In the processing of nanocomposites, high shear stresses at elevated tempera-tures orient two-dimensional nanoparticles like graphene. This orientationleads to anisotropic mechanical, thermal or barrier properties of the nanocom-posite. This anisotropy is addressed in this study by comparing graphene (few-layer graphene, FLG) with a nanoscaled carbon black (nCB) at a filler contentof 3 phr, by varying the vulcanization, and by comparing different FLG con-tents. Transmission electron microscopy gives insight into the qualitative ori-entation in the nanocomposite with FLG or nCB. The storage moduli paralleland normal to the orientation reveal the direction dependency of reinforce-ment through dynamic mechanical analysis (DMA). Dimensional swellingmeasurements show a restriction of the expansion parallel to the FLG orienta-tion, and an increased expansion normal to the orientation. The vulcanizationsystem and crosslinking determine the respective level of property values, andhigher crosslinking densities increase the anisotropy in DMA resulting invalues of up to 2.9 for the quantified anisotropy factor. With increasing FLGcontent, the anisotropy increases. A comparison of the results reveals swellingmeasurements as the most suitable method for the determination of anisot-ropy. Compared to recent literature, the presented processing induces higheranisotropy, leading to higher reinforcing effects in the direction of orientation KW - Natural rubber KW - Graphene KW - Nanocomposite KW - Mechanical properties KW - Swelling PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571522 DO - https://doi.org/10.1002/app.53753 SN - 1097-4628 VL - 140 IS - 16 SP - 1 EP - 15 PB - Wiley online library CY - Hoboken, New Jersey (USA) AN - OPUS4-57152 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Kunze, Ralf A1 - Hennecke, Manfred A1 - Kettner, A. A1 - Wendorff, J. H. T1 - On the thermal behaviour and thermo-oxidative stability of liquid crystalline triphenylene compounds N2 - Columnar discotic materials are considered for applications in the area of photoconductivity and light-emitting diodes. A major requirement is their stability at elevated temperatures and in the presence of oxygen. The thermal and thermo-oxidative behaviour of discotic triphenylene derivatives was investigated by us using various methods, in particular by chemiluminescence (CL), UV-vis absorption spectroscopy and in situ thermogravimetry-mass spectroscopy (TG-MS). Various degradation processes are described for increasing temperature, and their influences on functional properties are discussed. KW - Liquid crystal KW - Oxidation KW - Thermogravimetry PY - 1999 DO - https://doi.org/10.1002/(SICI)1099-0712(199903/04)9:2<55::AID-AMO366>3.3.CO;2-R SN - 1057-9257 SN - 1099-0712 VL - 9 IS - 2 SP - 55 EP - 64 PB - Wiley CY - Chichester AN - OPUS4-732 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Wachtendorf, Volker A1 - Hennecke, Manfred A1 - Grell, M. A1 - Bradley, D.D.C. T1 - Polarized fluorescence and orientational order parameters of a liquid-crystalline conjugated polymer N2 - We report a study of the orientational order of aligned thin films of the liquid crystalline conjugated polymer poly(9,9-dioctylfluorene). Steady state polarized fluorescence measurements were used to determine the orientational order parameter and . The influence of intermolecular and intramolecular excitation energy transfer on the degree of polarization is discussed. The role of film morphology is also examined by comparison of the results for glassy and crystalline films. KW - Liquid-cristalline conjugated Polymer KW - Polarized fluorescence measurements PY - 1999 SN - 1098-0121 SN - 0163-1829 SN - 0556-2805 SN - 1095-3795 SN - 1550-235X VL - 60 IS - 1 SP - 277 EP - 283 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-735 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -