TY - JOUR A1 - Braun, Ulrike A1 - Schartel, Bernhard A1 - Fichera, Mario Augusto A1 - Jäger, Christian T1 - Flame retardancy mechanisms of aluminium phosphinate in combination with melamine polyphosphate and zinc borate in glass-fibre reinforced polyamide 6,6 N2 - The fire retardancy mechanisms of aluminium diethylphosphinate in combination with melamine polyphosphate and zinc borate was analysed in glass-fibre reinforced polyamide 6,6. The influence of phosphorus compounds on the polyamide decomposition pathways was characterized using thermal analysis (TG), evolved gas analysis (TG–FTIR), and FTIR–ATR analysis of the residue. The Lewis acid–base interactions between the flame retardants, the amide unit, and the metal ions control the decomposition. The flammability (LOI, UL 94) and performance under forced-flaming conditions (cone calorimeter using different irradiations) were investigated. Fire residues were analysed with FTIR–ATR, SEM–EDX, and NMR. Aluminium phosphinate in polyamide 6,6 acts mainly by flame inhibition. Melamine polyphosphate shows some fuel dilution and a significant barrier effect. Using a combination of aluminium phosphinate and melamine polyphosphate results in some charring and a dominant barrier effect. These effects are improved in the presence of zinc borate due to the formation of boron–aluminium phosphates instead of aluminium phosphates. KW - Flame retardancy KW - Polyamide 6,6 KW - Metal phosphinate KW - Melamine polyphosphate KW - Zinc borate PY - 2007 SN - 0141-3910 SN - 1873-2321 VL - 92 IS - 8 SP - 1528 EP - 1545 PB - Applied Science Publ. CY - London AN - OPUS4-15707 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -