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 T2 - ACS Applied Polymer Materials 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. PB - ACS KW - Flexible polyurethane foam KW - Flame retardancy KW - Synergistic effect KW - Smoke behavior KW - Expandable graphite KW - Bio-based PY - 2023 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/57507 AN - OPUS4-57507 SN - 2637-6105 VL - 5 IS - 3 SP - 1891 EP - 1901 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany