TY - CHAP A1 - Rabe, Sebastian A1 - Sanchez-Olivares, G. A1 - Pérez-Chávez, R. A1 - Schartel, Bernhard ED - Laoutid, F. T1 - Natural Keratin and Coconut Fibres from Industrial Wastes in Flame Retarded Thermoplastic Starch Biocomposites N2 - Natural keratin fibres derived from Mexican tannery waste and coconut fibres from coconut processing waste were used as fillers in commercially available, biodegradable thermoplastic starch-polyester blend to obtain sustainable biocomposites. The morphology, rheological and mechanical properties as well as pyrolysis, flammability and forced flaming combustion behaviour of those biocomposites were investigated. In order to open up new application areas for these Kinds of biocomposites, ammonium polyphosphate (APP) was added as a flame retardant. Extensive flammability and cone calorimeter studies revealed a good flame retardance effect with natural fibres alone and improved effectiveness with the addition of APP. In fact, it was shown that replacing 20 of 30 wt. % of APP with keratin fibres achieved the same effectiveness. In the case of coconut fibres, a synergistic effect led to an even lower heat release rate and total heat evolved due to reinforced char residue. This was confirmed via scanning electron microscopy of the char structure. All in all, these results constitute a good approach towards sustainable and biodegradable fibre reinforced biocomposites with improved flame retardant properties. KW - Biomaterials KW - Biodegradation KW - Calorimetry KW - Composites KW - Flame retardance PY - 2020 SN - 978-3-03928-350-7 SN - 978-3-03928-351-4 SP - 45 EP - 66 PB - MDPI AN - OPUS4-50738 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 - Sanchez Olivares, G. A1 - Rockel, Daniel A1 - Calderas, F. A1 - Schartel, Bernhard T1 - Utilizing leather fibers from industrial wastes as bio-filler to improve flame retardancy in polypropylene N2 - Combining buffing leather fibers from industrial waste streams with ammonium polyphosphate and bentonite clay is proposed as a flame-retardant additive for polypropylene. The paper addresses how they can be processed into attractive composites with the desired mechanical properties. Buffing leather fibers function as a multifunctional bio-filler and as a synergist for the flame retardant, resulting in fire retardancy successful enough to increase the oxygen index (LOI) by up to 7 vol.-% and to achieve a V0 UL 94 classification. Impressively reduced heat release rates are obtained in the cone calorimeter at 50 kW/m2 irradiation; for instance, the maximum average rate heat evolved (MARHE) drops from 765 to below 200 kW m􀀀 2. The synergistic effects are quantified and shown to be very strong for LOI and MARHE. This work opens the door to use waste buffing leather fibers as a promising multifunctional and synergistic bio-filler. KW - Polypropylene KW - Flame retardancy KW - Industrial waste KW - Leather fibers KW - Bio-filler PY - 2024 DO - https://doi.org/10.1016/j.jiec.2023.11.008 SN - 1226-086X SN - 1876-794X VL - 132 SP - 148 EP - 160 PB - Elsevier B.V. AN - OPUS4-59556 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rockel, Daniel A1 - Sanchez Olivares, G. A1 - Schartel, Bernhard T1 - Improving the Flame Retardancy of Aluminium Trihydroxide in Thermoplastic Starch Biocomposites Using Waste Fibers and Silicon-Based Synergists N2 - The synergistic behavior of different silicon compounds is investigated in flame retardant biocomposites with aluminum trihydroxide (ATH) as the main flame retardant. The paper shows a new approach towards sustainable biocomposites through the implementation of thermoplastic starch (TPS), leather fibers from industrial waste streams, and non-hazardous flame retardants and synergists. In these multicomponent systems, the different components address different modes of action in the fire scenario. When ATH is partially substituted by glass frits or layered silicates, fire performance is enhanced without changing the total amount of filler in the polymer. In a biocomposite with 25 phr of fiber and 90 phr of ATH, substituting 5 phr of ATH for layered silicates increased the LOI from 31.5 vol % to 34.8 vol %, decreased the peak of heat release by 20%, and increased the UL 94 rating from V-1 to V-0. KW - Biocomposites KW - Sustainability KW - Waste streams KW - Flame retardancy KW - Synergism KW - Modes of action PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-605711 DO - https://doi.org/10.1021/acssusresmgt.4c00053 SN - 2837-1445 VL - 1 IS - 6 SP - 1131 EP - 1145 PB - ACS AN - OPUS4-60571 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sanchez Olivares, G. A1 - Battig, Alexander A1 - Goller, Sebastian M. A1 - Rockel, Daniel A1 - Ramirez Gonzáles, V. A1 - Schartel, Bernhard T1 - Imparting Fire Retardancy and Smoke Suppression to Leather during Tanning Processes N2 - Leather is considered a luxury good when used in seating and upholstery. To improve safety, flame retardancy in leather is usually achieved through various finishing processes such as spray or roller coating. These treatments require processing steps that cost time and are laborintensive. One avenue to achieving flame retardancy in leather is to add flame retardants during the tanning process. However, the influence on flame retardancy exerted by specific intumescent additives specifically added during leather tanning has yet to be investigated. This work explores the roles played by intumescent additive compounds in flame retarding leather when they are added during tanning instead of applied as a coating. Via a systematic investigation of various compound mixtures, the flame retardant effects in the condensed and the gas phases are elucidated. The results show a strong impact of melamine in the gas phase and of polyphosphates in the condensed phase. Their impact was quantified in fire and smoke analysis, showing a 14% reduction in the peak of heat release rate, strongly reduced burning lengths, and a 20% reduction in total smoke release compared to nontreated leather. These results illuminate the key role played by specific compounds in the flame retardancy of leather, particularly when they are added specifically during the tanning process instead of being applied as a coating. This method has great potential to reduce processing steps, lower costs, and improve material safety. KW - Leather KW - Fire protection KW - Intumescent additives KW - Smoke suppression PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-564777 DO - https://doi.org/10.1021/acsomega.2c05633 SN - 2470-1343 VL - 7 IS - 48 SP - 44156 EP - 44169 PB - ACS AN - OPUS4-56477 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gallo, Emanuela A1 - Sánchez-Olivares, G. A1 - Schartel, Bernhard T1 - Flame retardancy of starch-based biocomposites - aluminium hydroxide-coconut fiber synergy N2 - The use of coconut fiber (CF) agricultural waste was considered as an environmentally friendly and inexpensive alternative in flame retarded biocomposites. To decrease the high content of aluminum trihydrate (ATH) required, the thermal decomposition (thermogravimetry), flammability [oxygen index (LOI) and UL 94 test] and fire behavior (cone calorimeter) of a combination of CF and ATH were investigated in a commercial blend of thermoplastic starch (TPS) and cellulose derivatives. CF induced some charring activity, slightly decreasing the fire load and burning propensity in cone calorimeter test. ATH decomposes endothermically into water and inorganic residue. Significant fuel dilution as well as a pronounced residual protection layer reduces the fire hazards. Replacing a part of ATH with coconut fibers resulted in improved flame retardancy in terms of ignition, reaction to small flame, and flame-spread characteristics [heat release rate (HRR), fire growth rate (FIGRA), etc.]. The observed ATH and CF synergy opens the door to significant reduction of the ATH contents and thus to interesting flame retarded biocomposites. KW - Biocomposites KW - Flammability KW - Starch KW - Aluminium hydroxide KW - Coconut fiber PY - 2013 SN - 0032-2725 VL - 58 IS - 5 SP - 395 EP - 402 PB - Industrial chemistry research inst CY - Warszawa, Poland AN - OPUS4-28513 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 - CONF A1 - Sanchez-Olivares, G. T1 - Fire Behaviour and Viscoelasticity of Sustainable Thermoplastic Polyurethane Multicomponent Systems N2 - Main message: An interesting influence of viscoelastic properties on fire behavior of multicomponent systems based on thermoplastic polyurethane using industrial-waste leather fibers was observed. A detailed investigation on rheological properties, morphology, pyrolysis, flammability and forced flaming combustion highlighted that fire retardancy is best achieved when the multicomponent systems exhibit a predominant elastic behavior. Introduction: Multicomponent systems represent a sustainable alternative to traditional high-loaded flame retardant polymer materials, particularly in local areas where industrial-waste fibers are a problem.The final properties of those systems greatly depend on the melt blending process [1-2]. In this work,thermoplastic polyurethane multicomponent systems using industrial-waste leather fibers and a commercial flame-retardant additive were produced and investigated. Results and Discussion: According to rheological measurements, the viscoelastic behavior of the TPU multicomponent systems depends on the melt blending process conditions. Systems produced under low blending temperature profile and high rotational speed (TPU/5LF/5APP_T1/V3) display a predominant viscous behavior, meanwhile TPU/5LF/5APP_T1/V1 and TPU/5LF/5APP_T2/V2 samples, exhibit a more elastic one. The combination of LF and APP at low loadings (5 phr each) results in an important reduction on the peak of heat release rate (pHRR), total heat evolved (THE) and total smoke production (TSP) regarding to pure TPU. The UL94 vertical test pointed out that multicomponent systems with predominant elastic behavior (TPU/5LF/5APP_T1/V1 and TPU/5LF/5APP_T2/V2 samples) reached the V-0 rating, meanwhile for the system with the most viscous tendency (TPU/5LF/5APP_T1/V3), non-rating is obtained. Acknowledgement: Part of this work was funded by the Consejo Nacional de Humanidades Ciencias y Tecnologías (CONAHCYT), Mexico, grant number CF-2023-I-865. T2 - 20th European Meeting on Fire Retardant Polymeric Materials (FRPM2025) CY - Madrid, Spain DA - 03.06.2025 KW - TPU KW - Fire behavior KW - Viscoelastic properties KW - Leather fibers KW - Industrial wastes PY - 2025 AN - OPUS4-63400 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 - Two heads are better than one: Aluminum trihydroxide / phosphorous flame retardant combination in natural waste fiber biocomposites N2 - Future polymeric materials that replace fossil fuel-based engineering plastics demand the use of renewable sources as well as the implementation of key properties such as flame retardancy, processing, and mechanical properties. This study focuses on the combination of aluminum trihydroxide (ATH) and phosphorus-based flame retardants in compositable thermoplastic starch reinforced with sustainable multifunctional leather waste fibers. The flame retardants engender different flame-retardant modes of action, improving overall performance when combined. The partial substitution of ATH with phosphorous flame retardant allowed a reduction in flame retardant loading. Materials with 90 phr of ATH reached a limiting oxygen index of 31.5 vol.-% and a UL-94 rating of V-1, whereas the combination of 73 phr ATH and 7 phr of diphenyl ocytyl phosphate achieved a V-0 rating and a slightly reduced peak of heat release rate. This study demonstrates the potential of multicomponent systems implementing waste fiber–reinforced biocomposites. KW - Biocomposites KW - Flame retardancy KW - Phosphorous flame retardants KW - Synergism KW - Sustainability PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639084 DO - https://doi.org/10.1016/j.polymertesting.2025.108938 SN - 0142-9418 SN - 1873-2348 VL - 150 SP - 1 EP - 17 PB - Elsevier Ltd. AN - OPUS4-63908 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sanchez-Olivares, G. A1 - Rabe, Sebastian A1 - Pérez-Chávez, R. A1 - Calderas, F. A1 - Schartel, Bernhard T1 - Industrial-waste agave fibres in flame-retarded thermoplastic starch biocomposites N2 - Flame-retarded biocomposites of thermoplastic starch and natural fibres are successfully processed according to state-of-the-art extrusion and injection moulding. Using agave fibres and henequen fibres recovered from local industrial waste is a convincing contribution to sustainability. A systematically varied set of biocomposites is investigated comprehensively, e.g. electron microscopy is used for characterizing the morphology, rheology for the melt viscosity, tensile and impact resistance for the mechanical properties, thermal analysis for the pyrolysis, UL 94 burning chamber and oxygen index for the flammability, and cone calorimeter for the fire behaviour. Achieving sufficient mechanical properties was not the goal in our pre-competitive study but may be tackled by adding compatibilizer in future. The combination of well-dispersed natural fibres, aluminium diethylphosphinate (AlPi) and a special silicone synergist (Si) is proposed as promising innovative route for V-classified biocomposites. The flame-retardancy modes of action in the gas phase (fuel dilution and flame inhibition) and in the condensed phase (charring, protective layer formation) are discussed in detail, as is the role of combining the ingredients. This work is a convincing proof of principle of how to prepare industrial-waste fibres biocomposites, to apply the synergistic combination of AlPi and Si for future flame-retarded technical polymer materials that are based on renewable resources and compostable. KW - Flame-retardant biocomposites KW - Natural fibre KW - Biopolymer KW - Sustainability KW - Industrial-waste fibres KW - Flammability PY - 2019 DO - https://doi.org/10.1016/j.compositesb.2019.107370 SN - 1359-8368 VL - 177 SP - 107370 PB - Elsevier Ltd. AN - OPUS4-48777 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rabe, Sebastian A1 - Sánchez-Olivares, G. A1 - Pérez-Chávez, R. A1 - Schartel, Bernhard T1 - Natural keratin and coconut fibres from industrial wastes in flame retarded thermoplastic starch biocomposites N2 - Natural keratin fibres derived from Mexican tannery waste and coconut fibres from coconut processing waste were used as fillers in commercially available, biodegradable thermoplastic starch-polyester blend to obtain sustainable biocomposites. The morphology, rheological and mechanical properties as well as pyrolysis, flammability and forced flaming combustion behaviour of those biocomposites were investigated. In order to open up new application areas for these kinds of biocomposites, ammonium polyphosphate (APP) was added as a flame retardant. Extensive flammability and cone calorimeter studies revealed a good flame retardance effect with natural fibres alone and improved effectiveness with the addition of APP. In fact, it was shown that replacing 20 of 30 wt. % of APP with keratin fibres achieved the same effectiveness. In the case of coconut fibres, a synergistic effect led to an even lower heat release rate and total heat evolved due to reinforced char residue. This was confirmed via scanning electron microscopy of the char structure. All in all, these results constitute a good approach towards sustainable and biodegradable fibre reinforced biocomposites with improved flame retardant properties. KW - Biomaterials KW - Biodegradable KW - Calorimetry KW - Composites KW - Flame retardance PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-472518 DO - https://doi.org/10.3390/ma12030344 SN - 1996-1944 VL - 12 IS - 3 SP - 344, 1 EP - 24 PB - MDPI AN - OPUS4-47251 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -