TY - JOUR A1 - Perret, Birgit A1 - Schartel, Bernhard T1 - TGA-FTIR: From the investigation of pyrolysis to the elucidation of fire retardancy mechanisms KW - TGA-FTIR KW - Flammschutz KW - Pyrolyse PY - 2010 VL - 32 SP - 16 EP - 19 AN - OPUS4-23905 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Perret, Birgit A1 - Schartel, Bernhard T1 - TGA-FTIR: Détermination des mécanismes ignifuges par l´étude de la pyrolyse KW - TGA-FTIR KW - Flammschutz KW - Pyrolyse PY - 2010 VL - 32 SP - 16 EP - 19 AN - OPUS4-23906 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yu, D. A1 - Kleemeier, M. A1 - Wu, Guang Mei A1 - Schartel, Bernhard A1 - Liu, W.Q. A1 - Hartwig, A. T1 - The absence of size- dependency in flame retarded composites containing low-melting organic-inorganic glass and clay: Comparison between micro- and nanocomposites N2 - Due to optimised processing of epoxy based composite materials containing a low-melting organic–inorganic glass together with an organo clay, the size of the glass particles could be successfully reduced. Thus truly nano-dispersed composites were obtained, with glass particles in the range of 10 nm to 200 nm. The small particle size allowed efficient interaction of glass particles and organo clay layers. The flame retardancy as well as the thermo-mechanical properties were tested, and the results showed that the low-melting glass led to a remarkable reduction of peak heat release rate by forming an enhanced barrier layer. Nevertheless no further improvement could be achieved by lowering the particle size to the nanometre region. For good flame retardancy a microdispersion of the low-melting glass was already sufficient. KW - Epoxy resin KW - Nanocomposites KW - Low-melting glass KW - Clay KW - Flame retardancy PY - 2011 DO - https://doi.org/10.1016/j.polymdegradstab.2011.06.003 SN - 0141-3910 SN - 1873-2321 VL - 96 IS - 9 SP - 1616 EP - 1624 PB - Elsevier Ltd. CY - London AN - OPUS4-24211 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yu, D. A1 - Kleemeier, M. A1 - Wu, Guang Mei A1 - Schartel, Bernhard A1 - Liu, W.Q. A1 - Hartwig, A. T1 - Phosphorus and silicon containing low-melting organic-inorganic glasses improve flame retardancy of epoxy/clay composites N2 - New low-melting organic–inorganic glassy polymers containing phosphorus and silicon are synthesized by the reaction between phenylphosphonic acid and methyltrichlorosilane or methyltriethoxysilane. They possess both low-softening points and high onset decomposition temperatures, which are favorable for preparing flame retardant composites. Although the glass by itself is sensitive to water, the composites are not significantly affected in that way. For glass/clay/epoxy composites glass transition temperature (Tg) as well as storage modulus increase with the glass amount. The glasses improve flame retardancy significantly due to flame inhibition and the formation of fire residue working as protection layer during burning. The total heat evolved is reduced by 23–28% for using 5–15 wt.% glass and the maximum HRR even by 58–48%. The latter effect decreases with increasing glass amount due to an adulterate residue deformation. The combination of glass and clay is proposed as a possible route to enhance flame retardancy. KW - Clay KW - Epoxy resin KW - Flame retardancy KW - Organic-inorganic polymer KW - Low-melting glass PY - 2011 DO - https://doi.org/10.1002/mame.201100014 SN - 1438-7492 SN - 1439-2054 VL - 296 IS - 10 SP - 952 EP - 964 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-24516 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gallo, Emanuela A1 - Schartel, Bernhard A1 - Acierno, Domenico A1 - Russo, P. T1 - Flame retardant biocomposites: Synergism between phosphinate and nanometric metal oxides N2 - The known flame-retardant synergism between phosphorus-based additives and metal oxides, already used for petroleum-based plastics, has been extended to bio-based materials. The pyrolysis and the flame-retardancy properties of aluminium phosphinate (AlPi) in combination with nanometric iron oxide and antimony oxide on a poly(3-hydroxy-butyrate-co-3-hydroxyvalerate)/poly(butylene adipate-co-terephthalate) (PHBV/PBAT) blend were investigated. Better fire retardancy, ascribed to increases in intermediate char, favoured improvements in the UL 94 classification. Both the phosphorus and the nanofiller components participate simultaneously in the flame-retardancy mechanism: the first acting as flame inhibition in the gas phase, and the second promoting cross-linking in the solid phase. Redox reactions between iron oxide and the phosphinate additive were confirmed by XRD analysis and provided further evidence of the activity of metal compounds. KW - Aliphatic biopolyesters KW - Metal oxide KW - Flame retardancy KW - Aluminium phosphinate PY - 2011 DO - https://doi.org/10.1016/j.eurpolymj.2011.04.001 SN - 0014-3057 SN - 1873-1945 VL - 47 IS - 7 SP - 1390 EP - 1401 PB - Elsevier CY - Oxford AN - OPUS4-23889 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yu, D. A1 - Kleemeier, M. A1 - Wu, Guang Mei A1 - Schartel, Bernhard A1 - Liu, W.Q. A1 - Hartwig, A. T1 - A low melting organic-inorganic glass and its effect on flame retardancy of clay/epoxy composites N2 - A low-melting organic-inorganic glass with a high molecular weight soluble in solvents was synthesized by hydrolytic polycondensation of phenyltriethoxysilane followed by a subsequent heat treatment. Softening point and thermostability were strongly increased after heat treatment. The composites of glass/epoxy and glass/clay/epoxy were studied with respect to their thermal properties, fire behavior and mechanical properties. Heat release rate as measured by cone calorimetry was remarkably reduced in the presence of glass, relative to neat epoxy resin and polymer/clay composites. The combination of glass and clay is a promising approach. It showed mainly superposition and even synergistic effects in some fire properties for higher filler concentrations due to the formation of an enhanced barrier. The structure of residue was investigated by transmission electron microscopy (TEM). KW - Low-melting glass KW - Clay KW - Epoxy resin PY - 2011 DO - https://doi.org/10.1016/j.polymer.2011.03.033 SN - 0032-3861 SN - 1873-2291 VL - 52 IS - 10 SP - 2120 EP - 2131 PB - Elsevier Ltd. AN - OPUS4-23858 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gallo, Emanuela A1 - Schartel, Bernhard A1 - Braun, Ulrike A1 - Russo, P. A1 - Acierno, Domenico T1 - Fire retardant synergisms between nanometric Fe2O3 and aluminium phosphinate in poly(butylene terephthalate) N2 - The pyrolysis and the flame retardancy of poly(butylene terephthalate) (PBT) containing aluminum diethylphosphinate (AlPi) and nanometric Fe2O3 were investigated using thermal analysis, evolved gas analysis (Thermogravimetry-FTIR), flammability tests (LOI, UL 94), cone calorimeter measurements and chemical analysis of residue (FTIR). AlPi mainly acts as a flame inhibitor in the gas phase, through the release of diethylphosphinic acid. A small amount of Fe2O3 in PBT promotes the formation of a carbonaceous char in the condensed phase. The combination of 5 and 8 wt% AlPi, respectively, with 2 wt% metal oxides achieves V-0 classification in the UL 94 test thanks to complementary action mechanisms. Using PBT/metal oxide nanocomposites shows a significant increase in the flame retardancy efficiency of AlPi in PBT and thus opens the route to surprisingly sufficient additive contents as low as 7 wt%. KW - Poly(butylene terephthalate) (PBT) KW - Flammability KW - Metal oxide KW - Nanocomposite KW - Aluminum diethylphosphinate PY - 2011 DO - https://doi.org/10.1002/pat.1774 SN - 1042-7147 SN - 1099-1581 VL - 22 IS - 12 SP - 2382 EP - 2391 PB - John Wiley & Sons, Ltd. CY - Chichester AN - OPUS4-24915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Köppl, T. A1 - Brehme, Sven A1 - Wolff-Fabris, F. A1 - Altstädt, V. A1 - Schartel, Bernhard A1 - Döring, M. T1 - Structure-property relationships of halogen-free flame-retarded poly(butylene terephthalate) and glass fiber reinforced PBT N2 - Flame retardancy for thermoplastics is a challenging task where chemists and engineers work together to find solutions to improve the burning behavior without strongly influencing other key properties of the material. In this work, the halogen-free additives aluminum diethylphosphinate (AlPi-Et) and a mixture of aluminum phosphinate (AlPi) and resorcinol-bis(di-2,6-xylyl phosphate) (AlPi-H + RXP) are employed in neat and reinforced poly(butylene terephthalate) (PBT), and the morphology, mechanical performance, rheological behavior, and flammability of these materials are compared. Both additives show submicron dimensions but differ in terms of particle and agglomerate sizes und shapes. The overall mechanical performance of the PBT flame-retarded with AlPi-Et is lower than that with AlPi-H-RXP, due to the presence of larger agglomerates. Moreover, the flow behavior of the AlPi-Et/PBT materials is dramatically changed as the larger rod-like primary particles build a percolation threshold. In terms of flammability, both additives perform similar in the UL 94 test and under forced-flaming combustion. Nevertheless, AlPi-Et performs better than AlPi-H + RXP in the LOI test. The concentration required to achieve acceptable flame retardancy ranges above 15 wt %. KW - Polyesters KW - Fibers KW - Morphology KW - Structure–property relations KW - Flame retardance PY - 2012 DO - https://doi.org/10.1002/app.34910 SN - 0021-8995 SN - 1097-4628 VL - 124 IS - 1 SP - 9 EP - 18 PB - Wiley InterScience CY - Hoboken, NJ AN - OPUS4-25253 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bier, A.K. A1 - Bognitzki, M. A1 - Schmidt, A. A1 - Greiner, A. A1 - Gallo, Emanuela A1 - Klack, Patrick A1 - Schartel, Bernhard T1 - Synthesis, properties, and processing of new siloxane-substituted poly(p-xylylene) via CVD N2 - The synthesis of a disiloxane-functionalized [2.2]paracyclophane and its polymerization to the corresponding siloxane-substituted poly(p-xylylene) via chemical vapor deposition (CVD) has been described. Because of the enhanced solubility of the siloxane substituted poly(p-xylylene) analysis of the molecular structure by NMR, molecular weight, and polydispersity by gel permeation chromatography (GPC), and processing by film casting as well as nanofiber formation by electrospinning was possible. Structural isomers were found by NMR which was expected due to the isomeric mixture of the precursor. High molecular weights at moderate polydispersities were found by GPC which was unexpected for a vapor phase deposition polymerization. The amorphous morphology in combination with a low glass transition temperature led to high elongation at break for the siloxane substituted poly(p-xylylene). Significant difference for the wetting versus water was found for as-deposited films, solution cast films, and nanofibers obtained by electrospinning with contact angles up to 135° close to superhydrophobic behavior. KW - Poly(p-xylylene) KW - Siloxane functionalized PPX KW - Chemical vapor deposition KW - Difunctionalized [2.2]paracyclophanes KW - Gorham process PY - 2012 DO - https://doi.org/10.1021/ma2021369 SN - 0024-9297 SN - 1520-5835 VL - 45 IS - 2 SP - 633 EP - 639 PB - American Chemical Society CY - Washington, DC AN - OPUS4-25466 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lorenzetti, A. A1 - Modesti, M. A1 - Gallo, Emanuela A1 - Schartel, Bernhard A1 - Besco, S. A1 - Roso, M. T1 - Synthesis of phosphinated polyurethane foams with improved fire behaviour N2 - Both alkylphosphinates and inorganic phosphinates (based on sodium, calcium, magnesium or zinc) have been recently proposed as flame retardants for polyesters, polyamides and polyurethane foams as well. The main aim of this work was to compare the flame retardant effectiveness of inorganic (already proofed in PU foams) and organic phosphinates in PU foams which have never been used in polyurethane (PU) foams. The thermal stability in nitrogen and air as well as limiting oxygen index and cone calorimeter behaviour have been studied to assess the effectiveness of such flame retardants in PU foams. The results obtained showed that both inorganic and organic phosphinates are effective in enhancing fire behaviour of PU foams since they improve thermal stability, LOI and fire performance. Cone calorimetry highlighted the flame inhibition action in the gas phase due to the release of phosphorus-containing molecules. The better results obtained for inorganic phosphinate are probably related to the better quality of the char layer developed during burning, but may also be related to the higher phosphorus content of such flame retardant with respect the other ones. It was also verified that both inorganic and organic phosphinate containing N-synergic compound showed a fuel dilution effect, deriving from water and/or ammonia release in the gas phase. KW - Phosphinate KW - Polyurethane foam KW - Flame retardancy KW - Fire behaviour PY - 2012 DO - https://doi.org/10.1016/j.polymdegradstab.2012.07.026 SN - 0141-3910 SN - 1873-2321 VL - 97 IS - 11 SP - 2364 EP - 2369 PB - Applied Science Publ. CY - London AN - OPUS4-26735 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -