TY - THES A1 - Pawlowski, Kristin Helga T1 - Wirkungsmechanismen von Bisphenol-A-bis(diphenylphosphat) als Flammschutzmittel in Polycarbonat / Acrylnitril-Butadien-Styrol-Copolymerisat N2 - Die Suche nach halogenfreien Flammschutzmitteln für Polycarbonat / Acrylnitril- Butadien-Styrol-Copolymerisat (PC/ABS) führte zur Entwicklung von Triphenylphosphat (TPP), Resorcinol-bis(diphenylphosphat) (RDP) und Bisphenol-A- bis(diphenylphosphat) (BDP). Das unvollständige Wissen über die genauen Wirkungsmechanismen dieser Arylphosphate erschwert jedoch eine gezielte Optimierung der Systeme. In der vorliegenden Arbeit wurden die verschiedenen Flammschutzmechanismen von BDP in PC/ABS aufgeklärt. Ein Vergleich zwischen BDP mit RDP und TPP wurde gezogen und der Einfluss weiterer Additive wie Polytetrafluorethylen (PTFE), Böhmit, Zinkborat und Talk auf das Flammschutzverhalten von BDP herausgearbeitet. Dazu wurde das thermische Abbauverhalten mittels TG und TG-FTIR aufgeklärt. Die Entflammbarkeit wurde mit LOI- und UL 94-Tests bestimmt und das Brandverhalten anhand von Messungen im Cone Calorimeter bei unterschiedlichen Bestrahlungsstärken bewertet. Die Verbrennungsrückstände wurden mittels Festkörper-FTIR und Festkörper-NMR-Messungen charakterisiert. BDP wirkt in PC/ABS in der Gasphase durch Flammenvergiftung und in der festen Phase als Vernetzungsinitiator von PC. PTFE beeinflusst das Fließverhalten der Polymerschmelze und ermöglicht so die beste Klassifizierung im UL 94-Test von PC/ABS mit BDP. BDP ist thermisch stabiler als RDP und TPP und deshalb am aktivsten mit PC in der festen Phase. Böhmit verursacht durch eine H2O-Freisetzung Hydrolysereaktionen und wirkt somit leicht antagonistisch bezüglich der Festphasenaktivität von BDP. Zinkborat reagiert mit BDP zu alpha-Zinkphosphat und Borphosphat und unterdrückt so die Wirkung von BDP als Flammenvergifter und Vernetzungsinitiator. Die Zugabe von Talk bewirkt eine Verstärkung des Rückstandes, hat aber einen antagonistischen Effekt bezüglich der Gasphasenaktivität von BDP. Die Ergebnisse dieser Arbeit liefern ein detailliertes Verständnis der Flammschutzmechanismen von BDP und deren Abhängigkeit von der physikalischen und chemischen Umgebung. Mit diesem Wissen kann die Weiterentwicklung von BDP und anderen Arylphosphaten als Flammschutzmittel in PC/ABS gezielt optimiert werden. N2 - The search for halogen-free flame retardants for polycarbonate/acrylonitrile-butadiene- styrene (PC/ABS) has led to the development of triphenylphosphate (TPP), resorcinol bis(diphenyl phosphate) (RDP) and bisphenol A bis(diphenyl phosphate) (BDP).The lack of knowledge about the detailed flame retardant mechanisms of those arylphosphates makes it difficult to optimize those systems. In this thesis, the various flame retardancy mechanisms of BDP in PC/ABS have been clarified. BDP was compared to RDP and TPP and the influence of further additives (Polytetrafluoroethylene (PTFE), boehmite, zinc borate and talc) on the mechanisms of BDP were revealed. The thermal decomposition behaviour was clarified by means of TG and TG-FTIR. The flammability was determined by LOI and UL 94. The fire behaviour was evaluated by cone calorimeter measurements with different irradiations. Combustion residues were characterized by means of solid-state-FTIR and solid-state-NMR. BDP acts in PC/ABS as a flame inhibitor in the gas phase and as an initiator of cross linking in the condensed phase. PTFE influences the dripping behaviour of the polymer melt and enables PC/ABS + BDP to achieve the best classification in UL 94. BDP is thermally more stable than RDP and TPP and hence the most active flame retardant in the condensed phase. Boehmite releases water, which causes hydrolysis. This has an antagonistic effect concerning the condensed phase action of BDP. Zinc borate reacts with BDP to form alpha-zinc phosphate and borophosphate and suppresses the mechanisms of BDP as flame inhibitor and cross linking initiator. Talc stabilizes the char, but has an antagonistic effect on the gas phase action of BDP. The results gained from this thesis give a detailed understanding about the flame retardancy mechanisms of BDP and their dependence on the physical and chemical environment. They are fundamentals for a continuing development and improvement of aryl phosphates as flame retardants in PC/ABS. T3 - BAM Dissertationsreihe - 33 KW - PC/ABS KW - Entflammbarkeit KW - Pyrolyse KW - Acrylphosphate KW - Flammschutzmittel PY - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-1250 SN - 978-3-9812072-3-1 SN - 1613-4249 VL - 33 SP - 1 EP - 117 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-125 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pawlowski, Kristin A1 - Schartel, Bernhard T1 - Mechanisms of aryl phosphates as flame retardants in PC/ABS T2 - 17th Annual BCC Conference on Flame Retardancy; Recent Advances in Flame Retardancy of Polymeric Materials CY - Stamford, CT, USA DA - 2006-05-22 PY - 2006 AN - OPUS4-12553 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pawlowski, Kristin A1 - Schartel, Bernhard T1 - Flame retardancy mechanisms of bisphenol A bis(diphenyl phosphate) in polycarbonate/acrylonitrile-butadiene-styrene blends T2 - FRPM07 - 11th European Meeting on Fire Retardant Polymers CY - Bolton, England DA - 2007-07-04 PY - 2007 AN - OPUS4-15000 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pawlowski, Kristin A1 - Schartel, Bernhard T1 - Flame retardancy mechanisms of triphenyl phosphate, resorcinol bis(diphenyl phosphate) and bisphenol A bis(diphenyl phosphate) in polycarbonate/acrylonitrile-butadiene-styrene blends N2 - The flame retardancy mechanisms of three aryl phosphates, triphenyl phosphate (TPP), resorcinol bis(diphenyl phosphate) (RDP) and bisphenol A bis(diphenyl phosphate) (BDP), in a polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blend are investigated and compared. Further, the influence of polytetrafluorethylene (PTFE) on viscosity and thermal decomposition is discussed in the systems PC/ABS and PC/ABS + BDP. Mechanisms are proposed based on the results of various methods. Thermogravimetric analysis, Fourier transform infrared spectroscopy and kinetics are used to study the pyrolysis. The fire behaviour is studied by means of cone calorimeter measurements at different heat fluxes and the flammability is specified by limiting oxygen index (LOI) and UL 94. Rheology measurements are used to illuminate the changed dripping behaviour due to PTFE. TPP shows only a gas phase action. RDP shows mainly a gas phase action and some condensed phase action. BDP shows a crucial condensed phase action in addition to a gas phase action. TPP and RDP are somewhat superior in terms of flammability (LOI), whereas BDP shows superior performance in forced flaming combustion (cone calorimeter). Synergistic effects between PTFE and BDP are found. KW - Aryl phosphates KW - PC/ABS KW - Flame retardant KW - Pyrolysis KW - Flammability KW - TG-FTIR PY - 2007 U6 - https://doi.org/10.1002/pi.2290 SN - 0959-8103 SN - 1097-0126 SN - 0007-1641 VL - 56 IS - 11 SP - 1404 EP - 1414 PB - Wiley InterScience CY - Chichester, West Sussex AN - OPUS4-15857 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Pawlowski, Kristin A1 - Lyon, R.E. T1 - Pyrolysis combustion flow calorimeter: A tool to assess flame retarded PC/ABS materials? N2 - The pyrolysis combustion flow calorimeter (PCFC) as a tool for assessing the flammability of a polycarbonate (bisphenol A)/acrylonitrile–butadiene–styrene (PC/ABS) blend containing different flame retardants and additives was investigated. Strategies are proposed for analysing multi-step decomposition. The heat release capacity (HRC) and total heat release (HR), obtained by PCFC, are related to the char yield and the heat of complete combustion of the volatiles. Physical affects such as dripping, wicking, and sample thickness are not described, nor are chemical effects such as flame inhibition because pyrolysis and combustion are forced to completion on a small (milligram) sample. Varying the combustion temperature or oxygen concentration results in incomplete combustion as occuring in real fires. The correlations with flammability (UL 94, LOI) and forced flaming combustion in a cone calorimeter are discussed. The best correlation is found between HR and LOI. Reasonable correlation exists between HRC and char residue with the LOI and for HRC and HR with peak heat release rate (pHRR) in the cone calorimeter. Combining results from PCFC with those from oxygen bomb or cone calorimeter tests yields an additional understanding of fire behaviour. KW - Pyrolysis combustion flow calorimeter KW - Flammability KW - Combustion KW - Flame retardancy KW - PC/ABS PY - 2007 U6 - https://doi.org/10.1016/j.tca.2007.05.021 SN - 0040-6031 SN - 1872-762X VL - 462 IS - 1-2 SP - 1 EP - 14 PB - Elsevier CY - Amsterdam AN - OPUS4-15734 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Pawlowski, Kristin A1 - Perret, Birgit T1 - Flame Retardancy Mechanisms in Halogen-Free PC/ABS Blends KW - Fire Retardancy KW - PC/ABS KW - Arylphosphates KW - Cone Calorimeter KW - UL 94 KW - LOI KW - TG-FTIR PY - 2008 SN - 0743-0515 VL - 98 SP - 245 EP - 246 PB - Division of Polymeric Materials Science and Engineering, American Chemical Society CY - Washington, DC AN - OPUS4-17625 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Fichera, M.A. A1 - Jäger, Christian A1 - Schartel, Bernhard A1 - Braun, Ulrike A1 - Pawlowski, Kristin ED - Menachem Lewin, T1 - Solid-state NMR for monitoring the thermal decomposition of flame retarded polymers PY - 2007 SN - 1-59623-321-4 VL - I SP - 9 EP - 19 PB - BCC Research CY - Norwalk, CT, USA AN - OPUS4-17581 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schartel, Bernhard A1 - Braun, Ulrike A1 - Pawlowski, Kristin T1 - Phosphorus-Containing Polymeric Materials: The Impact of Pyrolysis on Flame Retardancy T2 - 11th International Conference "INTERFLAM 2007" CY - London, UK DA - 2007-09-03 KW - Flame Retardancy KW - Fire Retardancy KW - Flame Retardants KW - Decompositiion pathways KW - Pyrolysis KW - Phosphorus PY - 2007 SN - 978-0-9541216-8-6 SN - 978-0-9541216-9-3 SP - 71 EP - 78 PB - Interscience Communications Limited CY - London, UK AN - OPUS4-15761 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pawlowski, Kristin A1 - Schartel, Bernhard T1 - Flame retardancy mechanisms of aryl phosphates in combination with boehmite in bisphenol A polycarbonate/acrylonitrile-butadiene-styrene blends N2 - The influence of nano-dispersed 5 wt.% boehmite (AlOOH) and 5 wt.% AlOOH combined with bisphenol A bis(diphenyl phosphate) (BDP) in bisphenol A polycarbonate/acrylonitrile–butadiene–styrene (PC/ABS) + poly(tetrafluoroethylene) (PTFE), and 1 wt.% AlOOH with and without BDP, resorcinol bis(diphenyl phosphate) (RDP), and triphenyl phosphate (TPP), on PC/ABS + PTFE has been investigated. Possible flame retardancy mechanisms are revealed. Thermogravimetry (TG) and evolved gas analysis (TG-FTIR) are used to study pyrolysis, a cone calorimeter applying different external heat fluxes is used to investigate fire behaviour, and LOI and UL 94 are used to investigate flammability. Fire residues were investigated using ATR-FTIR. Adding 5 wt.% AlOOH decreases the peak heat release rate, as also has been reported for polymer nanocomposites with other layered structures. AlOOH releases water, and adding 5 wt.% AlOOH crucially influences thermal decomposition by enhancing the hydrolysis of PC and of BDP. For PC/ABS + PTFE + BDP + 5 wt.% AlOOH, the formation of AlPO4, for instance, results in antagonistic effects on the charring of PC + BDP, whereas synergy is observed in LOI. When only 1 wt.% AlOOH is added to the PC/ABS + PTFE with and without BDP, RDP and TPP, respectively, no significant influence is observed on thermal decomposition, UL 94, LOI or performance in the cone calorimeter. KW - Aryl phosphates KW - Boehmite KW - PC/ABS KW - Flammability KW - Nanocomposites KW - Flame retardant PY - 2008 U6 - https://doi.org/10.1016/j.polymdegradstab.2008.01.002 SN - 0141-3910 SN - 1873-2321 VL - 93 IS - 3 SP - 657 EP - 667 PB - Applied Science Publ. CY - London AN - OPUS4-17121 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pawlowski, Kristin A1 - Schartel, Bernhard T1 - Mechanisms of Aryl Phosphates as Flame Retardants in PC/ABS N2 - The pyrolysis and the fire behaviour of PC/ABS containing various aryl phosphates and their combinations with aluminium hydroxide oxide, talc and zinc borate were investigated. Main interest was focused on the flame retardant effect and mechanism of aryl phosphates (e.g. BDP) in PC/ABS, especially in combination with the other additives. Therefore the thermal and thermo oxidative decomposition was characterised by the means of thermogravimetry analysis and thermogravimetry coupled with infrared Fourier transform spectroscopy (TG-FTIR). The results were verified with further methods, e.g. pyrolysis-gaschromatography/mass spectroscopy (Py-GC/MS). Kinetic analysis and evolved gas analysis were used to study the pyrolysis mechanisms and to expose existent synergisms in the combined systems. The fire behaviour was investigated by cone calorimeter. The flammability was determined by LOI and UL 94. The chemical compositions of the residues were also examined. T2 - 17th Annual BCC Conference on Flame Retardancy CY - Stamford, CT, USA DA - 2006-05-22 KW - Aryl Phosphate KW - TG-FTIR KW - PC/ABS KW - Cone Calorimeter KW - Fire retardancy PY - 2006 SN - 1-59623-221-8 VL - 17 SP - 132 EP - 142 PB - BCC Research CY - Norwalk, Conn. AN - OPUS4-13982 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pawlowski, Kristin A1 - Schartel, Bernhard A1 - Fichera, Mario Augusto A1 - Jäger, Christian T1 - Flame retardancy mechanisms of bisphenol A bis(diphenyl phosphate) in combination with zinc borate in bisphenol A polycarbonate/Acrylonitrile-butadiene-styrene blends N2 - Bisphenol A polycarbonate/acrylonitrile–butadiene–styrene (PC/ABS) with and without bisphenol A bis(diphenyl phosphate) (BDP) and 5 wt.% zinc borate (Znb) were investigated. The pyrolysis was studied by thermogravimetry (TG), TG-FTIR and NMR, the fire behaviour with a cone calorimeter applying different heat fluxes, LOI and UL 94. Fire residues were examined with NMR. BDP affects the decomposition of PC/ABS and acts as a flame retardant in the gas and condensed phases. The addition of Znb results in an additional hydrolysis of PC. The fire behaviour is similar to PC/ABS, aside from a slightly increased LOI and a reduced peak heat release rate, both caused by borates improving the barrier properties of the char. In PC/ABS + BDP + Znb, the addition of Znb yields a borate network and amorphous phosphates. Znb also reacts with BDP to form alpha-zinc phosphate and borophosphates that suppress the original flame retardancy mechanisms of BDP. The inorganic–organic residue formed provides more effective flame retardancy, in particular at low irradiation in the cone calorimeter, and a clear synergy in LOI, whereas for more developed fires BDP + Znb become less effective than BDP in PC/ABS with respect to the total heat evolved. KW - Flame retardancy KW - PC/ABS KW - Aryl phosphate KW - Zinc borate KW - Flammability PY - 2010 U6 - https://doi.org/10.1016/j.tca.2009.10.007 SN - 0040-6031 SN - 1872-762X VL - 498 IS - 1-2 SP - 92 EP - 99 PB - Elsevier CY - Amsterdam AN - OPUS4-20746 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Perret, Birgit A1 - Pawlowski, Kristin A1 - Schartel, Bernhard T1 - Fire retardancy mechanisms of arylphosphates in polycarbonate (PC) and PC/acrylonitrile-butadiene-styrene N2 - The pyrolysis of polycarbonate (PC) and PC/acrylonitrile-butadiene-styrene (PC/ABS) with and without arylphosphates (triphenylphosphate TPP, resorcinol-bis(diphenyl phosphate) RDP and bisphenol A bis(diphenyl phosphate) BDP) is investigated by thermal analysis as key to understanding the flame retardancy mechanisms and corresponding structure-property relationships. The correspondence between the decomposition temperature range of arylphosphates and PC is pointed out as prerequisite for the occurrence of the reaction between arylphosphate and structures that are typical for the beginning of PC decomposition. Resulting cross-linking enhances charring in the condensed phase and competes with the alternative release of phosphate in the gas phase and thus flame inhibition. Flame inhibition was identified as the main flame retardancy mechanism. The additional condensed phase mechanisms optimise the performance. KW - Arylphosphates KW - BDP KW - Flame retardance KW - PC KW - PC/ABS PY - 2009 U6 - https://doi.org/10.1007/s10973-009-0379-7 SN - 1388-6150 SN - 1418-2874 SN - 0368-4466 SN - 1572-8943 VL - 97 IS - 3 SP - 949 EP - 958 PB - Kluwer Academic Publ. CY - Dordrecht AN - OPUS4-20330 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -