TY - JOUR A1 - Perret, Birgit A1 - Schartel, Bernhard A1 - Stöß, K. A1 - Ciesielski, M. A1 - Diederichs, J. A1 - Döring, M. A1 - Krämer, J. A1 - Altstädt, V. T1 - Novel DOPO-based flame retardants in high-performance carbon fibre epoxy composites for aviation JF - European polymer journal N2 - Two novel, halogen-free, phosphorus-based oligomeric flame retardants are investigated in the commercial epoxy resin RTM6 and ~70 wt.% carbon fibre RTM6 composites (RTM6-CF) with respect to pyrolysis and fire behaviour. The flame retardants are based on 9,10-dihydro-9-oxy-10-phosphaphenanthrene-10-oxide (DOPO) units linked to the star-shaped aliphatic ground body tetra-[(acryloyloxy)ethyl] pentarythrit (DOPP), or heterocyclic tris-[(acryloyloxy)ethyl] isocyanurate (DOPI), respectively. The glass transition temperature is reduced by adding DOPP and DOPI, but the mechanical properties of the composites (e.g. interlaminar shear strength (ILSS) and Gc in mode I and II) remain unchanged. Decomposition models are proposed based on mass loss, evolved gas analysis (TG–FTIR) and condensed product analysis (hot stage cell within FTIR). The fire behaviour is investigated comprehensively (UL 94, limiting oxygen index (LOI) and cone calorimeter). Both flame retardants act in the gas phase through flame inhibition and in the condensed phase through charring. The UL 94 of RTM6 is improved from HB to V-1 and V-0; the LOI from 25% to 34–38%. Peak heat release rate (PHRR) and total heat evolved (THE) are lowered by 31-49% and 40–44%, respectively. Adding CF increases the residue, reduces the THE, but suppresses the charring due to RTM6 and flame retardants. Thus the THE of RTM6-CF is reduced by about 25% when DOPI and DOPP are added. However, UL 94: V-0 and LOI of 45% and 48% are achieved with ~0.6 wt.% phosphorus. KW - Epoxy resin (RTM6) KW - DOPO KW - Carbon fibre reinforced composites KW - Mechanical properties KW - Flame retardancy PY - 2011 DO - https://doi.org/10.1016/j.eurpolymj.2011.02.008 SN - 0014-3057 SN - 1873-1945 VL - 47 IS - 5 SP - 1081 EP - 1089 PB - Elsevier Ltd. CY - Oxford AN - OPUS4-23548 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -