TY - JOUR A1 - Brehme, Sven A1 - Köppl, T. A1 - Schartel, Bernhard A1 - Altstädt, V. T1 - Competition in aluminium phosphinate-based halogen-free flame retardancy of poly(butylene terephthalate) and its glass-fibre composites JF - e-Polymers N2 - Aluminium diethylphosphinate (AlPi-Et) and inorganic aluminium phosphinate with resorcinol-bis(di-2,6-xylyl phosphate) (AlPi-H+RXP) were compared with each other as commercially available halogen-free flame retardants in poly(butylene terephthalate) (PBT) as well as in glass-fibre-reinforced PBT (PBT/GF). Pyrolysis behaviour and flame retardancy performance are reported in detail. AlPi-H+RXP released phosphine at very low temperatures, which can become a problem during processing. AlPi-Et provided better limiting oxygen index (LOI) values and UL 94 ratings for bulk and PBT/GF than AlPi-H+RXP. Both flame retardants acted via three different flame-retardancy mechanisms in bulk as well as in PBT/GF, namely, flame inhibition, increased amount of char, and a protection effect of the char. AlPi-Et was more efficient in decreasing the total heat evolved of PBT in the cone calorimeter test. AlPi-H+RXP reduced the peak heat release rate of PBT more efficiently than AlPi-Et. An optimum loading of AlPi-Et in PBT/GF was found, which was below the supplier's recommendation. This loading provides a maximum increase in LOI and a maximum decrease in total heat evolved. KW - Aluminium phosphinate KW - Flame retardancy KW - Glass-fibre composite KW - Poly(butylene terephthalate) PY - 2014 DO - https://doi.org/10.1515/epoly-2014-0029 SN - 1618-7229 VL - 14 IS - 3 SP - 193 EP - 208 PB - De Gruyter CY - [S.l.] AN - OPUS4-30648 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brehme, Sven A1 - Köppl, T. A1 - Schartel, Bernhard A1 - Fischer, O. A1 - Altstädt, V. A1 - Pospiech, D. A1 - Döring, M. T1 - Phosphorus polyester - an alternative to low-molecular-weight flame retardants in poly(butylene terephthalate)? JF - Macromolecular chemistry and physics N2 - Pyrolysis, fire behaviour and mechanical properties of a blend of poly(butylene terephthalate) (PBT) with a phosphorus polyester (PET-P-DOPO) are investigated and compared with PBT/aluminium diethylphosphinate (AlPi-Et) composites. The PBT/PET-P-DOPO is immiscible and exhibits gas-phase and condensed-phase activity, whereas AlPi-Et in PBT results mainly in flame inhibition. Only higher loadings of AlPi-Et yield significant condensed-phase activity. Using the same phosphorus content, PBT/PET-P-DOPO and PBT/AlPi-Et exhibit similar reductions in fire load (22%) and flame spread (17% assessed by fire growth rate, FIGRA), compared with PBT. In contrast to AlPi-Et, the addition of PET-P-DOPO does not decrease the tensile strength of PBT. Thus, PET-P-DOPO is an interesting alternative to low-molecular-weight flame retardants. KW - Aluminium phosphinate KW - Blends KW - 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide KW - Flame retardance KW - Polyesters PY - 2012 DO - https://doi.org/10.1002/macp.201200072 SN - 1022-1352 SN - 1521-3935 VL - 213 IS - 22 SP - 2386 EP - 2397 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-26982 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -