Halogen-free flame retarded poly(butylene terephthalate) (PBT) using metal oxides/PBT nanocomposites in combination with aluminium phosphinate

The flame retardancy of poly(butylene terephthalate) (PBT) containing aluminium diethlyphosphinate (AlPi) and/or nanometric metal oxides such as TiO2 or Al2O3 was investigated. In particular the different active flame retardancy mechanisms were discovered. Thermal analysis, evolved gas analysis (TG-FTIR), flammability tests (LOI, UL 94), cone calorimeter measurements and chemical analyses of residues (ATR-FTIR) were used. AlPi acts mainly in the gas phase through the release of diethylphosphic acid, which provides flame inhibition. Part of AlPi remains in the solid phase reacting with the PBT to phosphinate-terephthalate salts that decompose to aluminium phosphate at higher temperatures. The metal oxides interact with the PBT decomposition and promote the formation of additional stable carbonaceous char in the condensed phase. A combination of metal oxides and AlPi gains the better classification in the UL 94 test thanks to the combination of the different mechanisms.

[1]  A. I. Balabanovich,et al.  Fire Retardant Synergism Between Cyclic Diphosphonate Ester and Melamine in Poly(Butylene Terephthalate) , 2002 .

[2]  Bernhard Schartel,et al.  Flame Retardancy Mechanisms of Aluminium Phosphinate in Combination with Melamine Cyanurate in Glass-Fibre-Reinforced Poly(1,4-butylene terephthalate) , 2008 .

[3]  Bernhard Schartel,et al.  Development of fire‐retarded materials—Interpretation of cone calorimeter data , 2007 .

[4]  B. Schartel,et al.  Phosphonium‐modified layered silicate epoxy resins nanocomposites and their combinations with ATH and organo‐phosphorus fire retardants , 2006 .

[5]  S. Levchik,et al.  A Review of Recent Progress in Phosphorus-based Flame Retardants , 2006 .

[6]  E. Weil,et al.  Iron compounds in non-halogen flame-retardant polyamide systems , 2003 .

[7]  G. Botelho,et al.  A comparative study on the thermo-oxidative degradation of poly(ether-esters) , 2001 .

[8]  Matthew F. Bundy,et al.  Cone calorimeter analysis of UL‐94 V‐rated plastics , 2007 .

[9]  J. Yeh,et al.  Combustion and smoke emission properties of poly(ethylene terephthalate) filled with phosphorous and metallic oxides , 1998 .

[10]  L. Ferry,et al.  Red phosphorus/aluminium oxide compositions as flame retardants in recycled poly(ethylene terephthalate) , 2003 .

[11]  E. Leroy,et al.  Fire retardant systems in poly(methyl methacrylate): Interactions between metal oxide nanoparticles and phosphinates , 2007 .

[12]  I. Hamerton,et al.  RECENT DEVELOPMENTS IN THE CHEMISTRY OF HALOGEN-FREE FLAME RETARDANT POLYMERS , 2002 .

[13]  M. Lewin,et al.  Catalysis of intumescent flame retardancy of polypropylene by metallic compounds , 2003 .

[14]  Zhigang Lei,et al.  Effects of metal oxides on the pyrolysis of poly(ethylene terephthalate) , 2005 .

[15]  Marcelo M. Hirschler,et al.  Oxygen index : correlations to other fire tests , 1992 .

[16]  J. Brossas,et al.  Synthesis of fire retardant polymers without halogens , 1993 .

[17]  B. Schartel,et al.  Flame retardancy mechanisms of aluminium phosphinate in combination with melamine polyphosphate and zinc borate in glass-fibre reinforced polyamide 6,6 , 2007 .

[18]  S. Levchik,et al.  A review on thermal decomposition and combustion of thermoplastic polyesters , 2004 .

[19]  Charles A. Wilkie,et al.  Fire retardancy of polymeric materials , 2000 .

[20]  Heinz Sturm,et al.  Flame retardancy mechanisms of metal phosphinates and metal phosphinates in combination with melamine cyanurate in glass‐fiber reinforced poly(1,4‐butylene terephthalate): the influence of metal cation , 2008 .

[21]  T. Arii,et al.  The effect of humidity on thermal decomposition of terephthalate polyester , 2004 .

[22]  M. Bras.  Fire retardancy of polymers : new applications of mineral fillers , 2007 .

[23]  Giovanni Camino,et al.  Effect of glass fibres and fire retardant on the combustion behaviour of composites, glass fibres–poly(butylene terephthalate) , 1998 .

[24]  G. F. Levchik,et al.  Mechanism of Action of Phosphorus‐based Flame Retardants in Nylon 6. III. Ammonium Polyphosphate/Manganese Dioxide , 1996 .

[25]  Menachem Lewin,et al.  Synergism and catalysis in flame retardancy of polymers , 2001 .

[26]  B. Schartel,et al.  Some comments on the use of cone calorimeter data , 2005 .