TY - JOUR A1 - Despinasse, Marie-Claire A1 - Schartel, Bernhard T1 - Aryl phosphate-aryl phosphate synergy in flame-retarded bisphenol A polycarbonate/acrylonitrile-butadiene-styrene JF - Thermochimica Acta N2 - The pyrolysis and fire performance of bisphenol A polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) flame-retarded by a mixture of two aryl bisphosphates were investigated by thermogravimetry-coupled with FTIR, oxygen index (LOI), UL 94 and cone calorimeter. Both flame retardants, bisphenol A bis (diphenyl phosphate) BDP and hydroquinone bis (diphenyl phosphate) HDP, show gas-phase and condensed-phase actions. When mixed together at different ratios, a synergy is observed in terms of pyrolysis and fire residues as well as in effective heat of combustion (THE/ML). The synergisms were quantified and confirmed mathematically by the evaluation of the synergistic effect index (SE). All LOI values for the flame-retarded blends are between 29% and 32%, as opposed to 23% for PC/ABS, and UL94 testing results in V-0 at 1.6 mm instead of HB. Investigations on the binary system BDP + HDP reveal that BDP and HDP interact with each other, yielding stable intermediate products which are proposed to increase the thermal stability of the PC/ABS + BDP/HDP blends. Oligomeric phosphate esters are presumed to form via transesterification. KW - Flame retardancy KW - PC/ABS KW - Pyrolysis KW - Aryl phosphate KW - Synergy KW - Combustion PY - 2013 DO - https://doi.org/10.1016/j.tca.2013.04.006 SN - 0040-6031 SN - 1872-762X VL - 563 SP - 51 EP - 61 PB - Elsevier CY - Amsterdam AN - OPUS4-28515 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 JF - Polymer degradation and stability 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 DO - 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 - 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 JF - Polymer International 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 DO - 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 - 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 JF - Thermochimica Acta 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 DO - 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 JF - Journal of thermal analysis and calorimetry 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 DO - 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 - 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? JF - Thermochimica Acta 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 DO - 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 JF - PMSE preprints 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 - JOUR A1 - Wawrzyn, Eliza A1 - Schartel, Bernhard A1 - Ciesielski, M. A1 - Kretzschmar, B. A1 - Braun, Ulrike A1 - Döring, M. T1 - Are novel aryl phosphates competitors for bisphenol A bis(diphenyl phosphate) in halogen-free flame-retarded polycarbonate/acrylonitrile-butadiene-styrene blends? JF - European polymer journal N2 - The reactivity of the flame retardant and its decomposition temperature control the condensed-phase action in bisphenol A polycarbonate/acrylonitrile–butadiene–styrene/polytetrafluoroethylene (PC/ABSPTFE) blends. Thus, to increase charring in the condensed phase of PC/ABSPTFE + aryl phosphate, two halogen-free flame retardants were synthesized: 3,3,5-trimethylcyclohexylbisphenol bis(diphenyl phosphate) (TMC-BDP) and bisphenol A bis(diethyl phosphate) (BEP). Their performance is compared to bisphenol A bis(diphenyl phosphate) (BDP) in PC/ABSPTFE blend. The comprehensive study was carried out using thermogravimetry (TG); TG coupled with Fourier transform infrared spectrometer (TG-FTIR); the Underwriters Laboratory burning chamber (UL 94); limiting oxygen index (LOI); cone calorimeter at different irradiations; tensile, bending and heat distortion temperature tests; as well as rheological studies and differential scanning calorimeter (DSC). With respect to pyrolysis, TMC-BDP works as well as BDP in the PC/ABSPTFE blend by enhancing the cross-linking of PC, whereas BEP shows worse performance because it prefers cross-linking with itself rather than with PC. As to its fire behavior, PC/ABSPTFE + TMC-BDP presents results very similar to PC/ABSPTFE + BDP; the blend PC/ABSPTFE + BEP shows lower flame inhibition and higher total heat evolved (THE). The UL 94 for the materials with TMC-BDP and BDP improved from HB to V0 for specimens of 3.2 mm thickness compared to PC/ABSPTFE and PC/ABSPTFE + BEP; the LOI increased from around 24% up to around 28%, respectively. BEP works as the strongest plasticizer in PC/ABSPTFE, whereas the blends with TMC-BDP and BDP present the same rheological properties. PC/ABSPTFE + TMC-BDP exhibits the best mechanical properties among all flame-retarded blends. KW - Polycarbonate (PC) KW - Aryl phosphate KW - Flame retardancy KW - Pyrolysis KW - PC/ABS PY - 2012 DO - https://doi.org/10.1016/j.eurpolymj.2012.06.015 SN - 0014-3057 SN - 1873-1945 VL - 48 IS - 9 SP - 1561 EP - 1574 PB - Elsevier CY - Oxford AN - OPUS4-26292 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -