TY - JOUR A1 - Chan, Yin Yam A1 - Korwitz, A. A1 - Pospiech, D. A1 - Schartel, Bernhard T1 - Flame Retardant Combinations with Expandable Graphite/ Phosphorus/CuO/Castor Oil in Flexible Polyurethane Foams N2 - A series of flexible polyurethane foams (FPUFs) were prepared with single and different combinations of flame retardants and additives. Expandable graphite (EG), phosphorous polyol (OP), copper (II) oxide (CuO), and/or castor oil (CAS) were added to FPUF during the foam preparation in a one-step process. The purpose of the study is to evaluate the synergistic effects of the flame retardants, additives, and the presence of bio-based content on the mechanical properties, flame retardancy, and smoke behavior of FPUFs. The combination of 10 wt % EG and 5 wt % OP in FPUF significantly improves the char yield. In the cone calorimeter experiment, the char yield is nearly three times higher than that with 10 wt % EG alone. The smoke behavior is additionally evaluated in a smoke density chamber (SDC). Comparing the samples with a single flame retardant, 10 wt % EG in FPUF considerably reduces the amount of smoke released and the emission of toxic gases. Replacing the amount of 10 wt % polyether polyol in FPUF with CAS maintains the physical and mechanical properties and fire behavior and enhances the bio-based content. The presence of 0.1 wt % CuO in FPUF effectively reduces the emission of hydrogen cyanide. As a result, this study proposes a multicomponent flame retardant strategy for FPUF to enhance the biomass content and address the weaknesses in flame retardancy, smoke, and toxic gas emissions. A starting point is disclosed for future product development. KW - Flexible polyurethane foam KW - Flame retardancy KW - Synergistic effect KW - Smoke behavior KW - Expandable graphite KW - Bio-based PY - 2023 U6 - https://doi.org/10.1021/acsapm.2c01969 SN - 2637-6105 VL - 5 IS - 3 SP - 1891 EP - 1901 PB - ACS AN - OPUS4-57507 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Korwitz, A. A1 - Pospiech, D. A1 - Kretzschmar, B. A1 - Vollmerhausen, Dominik A1 - Schartel, Bernhard T1 - Using the combination of phosphorus polymers and nanocomposite concept to tailor the flame retardancy of polyesters N2 - The potential of nanocomposites, i.e. mixtures of nanoobjects with acceptable distribution in a polymer matrix, with respect to flame retardancy was discovered in an already early stage of nanocomposite reseach. Since then, a variety of nanocomposites often in combination with conventional flame retardants (FRs) and their effect on the burning behavior has been described. Here, we show the application of this concept to enhance the flame retardancy of poly(butylene terephthalate) (PBT) and poly(butylene succinate) (PBS) using suitable phosphorus-containing polyesters as FR. The materials studied were prepared by melt compounding in a twin screw extruder using either a mixture of polymer matrix, phosphorus polymer and nanomaterial (direct compounding) or a mixture of a pre-formed batch of phosphorus polymer with nanomaterial and the polymer matrix (batch compounding). The second method has been shown to be very effective if batches prepared by in-situ nanocomposite synthesis via melt transesterification polycondensation were employed. Modified organoclay (montmorillonite, OMMT) as well as multiwalled carbon nanotubes were used as nanoobjects. Organic modification of MMT resulted in better exfoliation and distribution within the poylmer matrix than observed with pure sodium MMT. However, modification with phosphorus-containing modifiers dis not support exfoliation due to high interaction between modifier and clay. Analysis of the in-situ prepared nanocomposites of OMMT (Cloisite 30B) with the phosphorus polyester PET-P-DOPO by thermogravimetry, FTIR and pyrolysis-GC/MS showed that OMMT did not alter the principal decomposition pathway of the polyester, but shifted the onset of decomposition to lower temperature (due to the fast decomposition of the tertiary ammonium compound) and increased the amount of char. The fire behavir as observed by microscale combustion calorimetry (MCC) was altered and resulted in significant decrease of heat release capacity. In-situ prepared batches of the phosphorus polyester PET-P-DOPO with 20 wt.-% OMMT and with MWCNT (1 wt.-%) were blended with PBT in the ratio 25/75 wt/wt to achieve a phosphorus concentration of 1.5 wt.-%. The nanocomposites were injection molded into plates for cone calorimeter measurements and examined using 50 kW/m2. In all samples, a reduction of toral heat evolved and total heat evolved/total mass loss (THE/TML) was observed. Addition of OMMT improved the char, which was even more pronounced in combination with PET-P-DOPO as illustrated in Figure 1. Blends containing PET-P-DOPO additionally showed intumescence. In all cases, a significant reduction of FIGRAmax was obtained. The addition of nanomaterials (both OMMT and MWCNT) to PBT/PET-P-DOPO reduced the effective heat of combustion (THE/TML) from 1.7 to 1.5 MJ/m2. T2 - FRPM 2017, 16th European Meeting on Fire Retardant Polymeric Materials CY - Manchester, UK DA - 03.07.2017 KW - Nanocomposite KW - Phosphorus polymers KW - Flame retardancy PY - 2017 AN - OPUS4-40951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pospiech, D. A1 - Fischer, O. A1 - Korwitz, A. A1 - Hoffmann, T. A1 - Köppl, T. A1 - Altstädt, V. A1 - Ciesielski, M. A1 - Döring, M. A1 - Brehme, Sven A1 - Schartel, Bernhard A1 - Vollmerhausen, D. T1 - Designed flame retardancy with phosphorus polymers N2 - Polymeric flame retardants offer the possibility to match effective flame retardancy with the requirements of new regulations. Synthesis, properties and efficiency in polymer matrices are discussed for two systems, epoxy resins as well as poly(butylene terephthalate). T2 - 25th Annual conference: Recent advances in flame retardancy of polymeric materials CY - Stamford, Connecticut, USA DA - 18.05.2014 KW - Flame retardancy KW - Phosphorus polymer KW - Poly(butylene terephthalate) KW - Epoxy resin PY - 2014 SP - 1 EP - 5 AN - OPUS4-30951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -