TY - JOUR A1 - Köppl, T. A1 - Brehme, Sven A1 - Wolff-Fabris, F. A1 - Altstädt, V. A1 - Schartel, Bernhard A1 - Döring, M. T1 - Structure-property relationships of halogen-free flame-retarded poly(butylene terephthalate) and glass fiber reinforced PBT N2 - Flame retardancy for thermoplastics is a challenging task where chemists and engineers work together to find solutions to improve the burning behavior without strongly influencing other key properties of the material. In this work, the halogen-free additives aluminum diethylphosphinate (AlPi-Et) and a mixture of aluminum phosphinate (AlPi) and resorcinol-bis(di-2,6-xylyl phosphate) (AlPi-H + RXP) are employed in neat and reinforced poly(butylene terephthalate) (PBT), and the morphology, mechanical performance, rheological behavior, and flammability of these materials are compared. Both additives show submicron dimensions but differ in terms of particle and agglomerate sizes und shapes. The overall mechanical performance of the PBT flame-retarded with AlPi-Et is lower than that with AlPi-H-RXP, due to the presence of larger agglomerates. Moreover, the flow behavior of the AlPi-Et/PBT materials is dramatically changed as the larger rod-like primary particles build a percolation threshold. In terms of flammability, both additives perform similar in the UL 94 test and under forced-flaming combustion. Nevertheless, AlPi-Et performs better than AlPi-H + RXP in the LOI test. The concentration required to achieve acceptable flame retardancy ranges above 15 wt %. KW - Polyesters KW - Fibers KW - Morphology KW - Structure–property relations KW - Flame retardance PY - 2012 U6 - https://doi.org/10.1002/app.34910 SN - 0021-8995 SN - 1097-4628 VL - 124 IS - 1 SP - 9 EP - 18 PB - Wiley InterScience CY - Hoboken, NJ AN - OPUS4-25253 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -