TY - JOUR A1 - Schartel, Bernhard A1 - Pötschke, P. A1 - Knoll, Uta A1 - Abdel-Goad, M. T1 - Fire behaviour of polyamide 6/multiwall carbon nanotube naocomposites N2 - Nanocomposites of polyamide 6 with 5 wt.% multiwall carbon nanotubes are investigated to clarify their potential as regards the fire retardancy of polymers. The nanocomposites are investigated using SEM, electrical resistivity, and oscillatory shear rheology. The pyrolysis is characterized using thermal analysis. The fire behaviour is investigated with a cone calorimeter using different external heat fluxes, by means of the limiting oxygen index and the UL 94 classification. The fire residue is characterized using SEM. The comprehensive fire behaviour characterization not only allows the materials’ potential for implementation in different fire scenarios and fire tests to be assessed, but also provides detailed insight into the active mechanisms. The increased melt viscosity of the nanocomposites and the fibre-network character of the nanofiller are the dominant mechanisms influencing fire performance. The changes are found to be adjuvant with respect to forced flaming conditions in the cone calorimeter, but also deleterious in terms of flammability. KW - Carbon Nanotubes KW - Nanocomposites KW - Flame retardancy KW - Rheology KW - Thermal Analysis KW - Fire retardancy KW - Cone Calorimeter PY - 2005 DO - https://doi.org/10.1016/j.eurpolymj.2004.11.023 SN - 0014-3057 SN - 1873-1945 VL - 41 IS - 5 SP - 1061 EP - 1070 PB - Elsevier CY - Oxford AN - OPUS4-7142 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Braun, Ulrike A1 - Knoll, Uta A1 - Bartholmai, Matthias A1 - Goering, Harald A1 - Neubert, Dietmar A1 - Pötschke, P. T1 - Mechanical, Thermal, and Fire Behavior of Bisphenol A Polycarbonate/Multiwall Carbon Nanotube Nanocomposites N2 - Nanocomposites of bisphenol A polycarbonate with 2, 4, 6, and 15 wt% multiwall carbon nanotubes (MWNT) and their use in fire retardancy are investigated. Their thermal behavior and pyrolysis are characterized using thermogravimetry, differential scanning calorimeter, oscillatory shear rheology, and dynamic mechanical analysis. The flammability is addressed using LOI and UL 94; the fire behavior, with a cone calorimeter using different irradiation. With increasing MWNT content the storage modulus is increased (10-20%) and melt viscosity increases by several orders of magnitude, particularly for low shear rates. The melt flow, dripping, and deformation during fire are hindered, which influences UL 94 and cone calorimeter results. The peak heat release rate is reduced up to 40-50% due to an improved barrier for small amounts (2 wt%) of MWNT and for low irradiation, whereas the effect is reduced for increasing irradiation and nearly vanishes for increasing filling. Adjuvant but also deleterious mechanisms result in the complex dependency on the MWNT content. Significant flame retardancy effects are specific and limited to only some fire properties. This study allows the materials' potential for implementation in different fire scenarios and tests to be assessed and provides insight into active mechanisms. KW - Flame retardancy KW - Nanocomposite KW - Carbon multiwall nanotube (MWNT) KW - Cone Caorimeter KW - Flammability PY - 2008 DO - https://doi.org/10.1002/pen.20932 SN - 0032-3888 SN - 1548-2634 VL - 48 IS - 1 SP - 149 EP - 158 PB - Wiley CY - Hoboken, NY AN - OPUS4-16365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -