TY - GEN A1 - Schartel, Bernhard A1 - Bartholmai, Matthias A1 - Braun, Ulrike ED - Le Bras, M. T1 - Barrier effects for the fire retardancy of polymers T2 - 9th European Meeting on Fire Retardancy and Protection of Materials CY - Lille, France DA - 2003-09-15 KW - Fire retardancy KW - Nanocomposites KW - Red Phosphorus KW - Mg(OH)2 KW - Cone Calorimeter KW - LOI PY - 2005 SN - 0-85404-582-1 VL - 9 SP - 264 EP - 275 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-7377 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Bartholmai, Matthias A1 - Knoll, Uta T1 - Some comments on the main fire retardancy mechanisms in polymer nanocomposites N2 - Barrier formation and increasing the melt viscosity are addressed as the two main general fire retardancy mechanisms of polymer nanocomposites. They result in specific impacts on fire properties that consequentially cause varying flame retardancy efficiency in different fire tests. The barrier formation retards mainly flame spread (peak of heat release rate) in developing fires, but does not reduce fire load (total heat evolved), ignitability or flammability (limiting oxygen index, UL 94). Furthermore, this flame retardancy effect increases with increasing irradiation and vanishes with decreasing irradiation. The increased melt viscosity prevents dripping, which is beneficial or disadvantageous depending on the fire test used. In some test, it become the dominant influence, transforming self-extinguishing samples into flammable materials or causing wicking. Advantages and the limits are sketched comprehensively for exploiting the main general fire retardancy mechanisms of polymer nanocomposites. It is concluded that barrier formation and changing the melt viscosity in nanocomposites are not sufficient for most applications, but must be accompanied by additional mechanisms in special systems or in combination with other flame retardants. KW - Flame retardance KW - Nanocomposites KW - Organoclay KW - Cone calorimeter KW - Flammability PY - 2006 DO - https://doi.org/10.1002/pat.792 SN - 1042-7147 SN - 1099-1581 VL - 17 IS - 9-10 SP - 772 EP - 777 PB - John Wiley & Sons, Ltd. CY - Chichester AN - OPUS4-13868 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bartholmai, Matthias A1 - Schartel, Bernhard T1 - Assessing the performance of intumescent coatings using bench-scaled cone calorimeter and finite difference simulations N2 - A method was developed to assess the heat insulation performance of intumescent coatings. The method consists of temperature measurements using the bench-scaled experimental set-up of a cone calorimeter and finite difference simulation to calculate the effective thermal conductivity dependent on time/temperature. This simulation procedure was also adapted to the small scale test furnace, in which the standard time-temperature curve is applied to a larger sample and thus which provides results relevant for approval. Investigations on temperature and calculated effective thermal conduction were performed on intumescent coatings in both experimental set-ups using various coating thicknesses. The results correspond to each other as well as showing the limits of transferability between both fire tests. It is shown that bench-scaled cone calorimeter tests are a valuable tool for assessing and predicting the performance of intumescent coatings in larger tests relevant for approval. The correlation fails for processes at surface temperatures above 750°C, which are not reached in the cone calorimeter, but are attained in the small scale furnace set-up. KW - Intumescent coatings KW - Cone calorimetry KW - Numerical analysis KW - Small scale test furnace PY - 2007 SN - 0308-0501 SN - 1099-1018 VL - 31 IS - 3 SP - 187 EP - 205 PB - Heyden CY - London AN - OPUS4-14645 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -