TY - JOUR A1 - Artner, J. A1 - Ciesielski, M. A1 - Walter, O. A1 - Döring, M. A1 - Perez, R.M. A1 - Sandler, J.K.W. A1 - Altstädt, V. A1 - Schartel, Bernhard T1 - A novel DOPO-based diamine as hardener and flame retardant for epoxy resin systems N2 - 10-Ethyl-9-oxa-10-phosphaphenanthrene-10-oxide (1) can be nitrated using acetic anhydride and fuming nitric acid. The nitro group is reduced using palladium on charcoal and hydrogen. These reaction conditions are used for the synthesis of an analogous DOPO-based diaminic hardener (7). An evaluation of the curing behavior, mechanical properties and flammability of a neat resin made of DGEBA and 7 (DGEBA + 7) and of a carbon fiber-reinforced resin made of DGEBA, 4,4-diaminodiphenylsulfon (DDS) and 7 (DGEBA + DDS + 7) shows the potential of this hardener to lead to flame-retardant systems while keeping relevant properties on a high level; especially when compared to a similar system (DGEBA + DDS + 1). KW - Composites KW - Epoxy resins KW - Synthesis KW - Flame retardancy KW - Mechanical properties PY - 2008 DO - https://doi.org/10.1002/mame.200700287 SN - 1438-7492 SN - 1439-2054 VL - 293 IS - 6 SP - 503 EP - 514 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-17624 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Braun, Ulrike A1 - Balabanovich, Aliaksandr A1 - Artner, J. A1 - Ciesielski, M. A1 - Döring, M. A1 - Perez, R.M. A1 - Sandler, J.K.W. A1 - Altstädt, V. T1 - Pyrolysis and fire behaviour of epoxy systems containing a novel 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide-(DOPO)-based diamino hardener N2 - Highly soluble 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide-(DOPO)-based diamino hardener (2), bearing its amino groups directly on the DOPO framework, is investigated with respect to its use as a reactive flame retardant in thermosets. A mechanism for decomposition of the corresponding phosphorus-modified epoxy resin system based on a diglycidylether of bisphenol A DGEBA and 2 (DGEBA/2) is proposed and compared to the systems using DGEBA and 4,4'-diaminodiphenylsulfon (DGEBA/DDS) and to a similar system based on the structurally comparable non-reactive DOPO-based compound (DGEBA/DDS/1). Additive 1 changed the decomposition characteristics of the epoxy resin only slightly and phosphorus was released. Incorporating 2 induces two-step decomposition and most of the phosphorus remains in the residue. Furthermore, the fire behaviour of neat epoxy resin systems and a representative carbon fibre-reinforced composite based on DGEBA, DDS and 2 (DGEBA/DDS/2) were examined and compared to that of the analogous composite systems based on DGEBA/DDS and DGEBA/DDS/1. Based on different flame retardancy mechanisms both the reactive compound 2 and the additive compound 1 improve flammability (increase in LOI >13% and achieving V-1 behaviour) of the epoxy resin and composites. Under forced flaming only the flame inhibition of the additive compound 1 acts sufficiently. Lastly, the superior key mechanical properties of the epoxy resin and composite based on 2 are sketched. KW - Decomposition KW - DOPO KW - Flame retardancy KW - Composites KW - Thermosets PY - 2008 DO - https://doi.org/10.1016/j.eurpolymj.2008.01.017 SN - 0014-3057 SN - 1873-1945 VL - 44 IS - 3 SP - 704 EP - 715 PB - Elsevier CY - Oxford AN - OPUS4-16708 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -