Synergistic fire retardancy of colemanite, a natural hydrated calcium borate, in high-impact polystyrene containing brominated epoxy and antimony oxide

2011-05-01
Kaynak, Cevdet
Show full item record
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
207
views
0
downloads
This study explores for the first time the synergistic fire retardant action of natural hydrated calcium borate, namely the mineral colemanite, which partially replaces antimony oxide in brominated flame retardant high-impact polystyrene compounds. Various antimony oxide to hydrated calcium borate ratios were employed keeping the brominated flame retardant additive at a constant loading level. With partial colemanite substitution for antimony oxide, lower heat release rate, total heat evolved and fire growth index was obtained under forced flaming fire conditions. Synergism was also seen in limiting oxygen index along with maintained V-0 classification in UL-94 tests. Regarding fire behaviour and flammability ratings, a large antimony oxide to calcium borate ratio provided ultimate fire retardant performance whereas magnitudes of synergism in average heat release rate and total heat evolved tend to be higher towards a smaller ratio. Effective heats of combustion and structural/morphological characterization of fire residues ascribed the underlying mechanism demonstrated by hydrated calcium borate to the formation of a consolidated residue that co-operates with the dominant gas phase fire retardancy originating from bromine antimony synergism. It is thus proposed that coupling is achieved between gas phase and condensed phase modes of action increasing the overall fire retardant effectiveness. Along with enhanced fire retardancy, thermal stability and mechanical properties were satisfactorily maintained with the use of hydrated calcium borate at a variety of loading levels in compounds.
Flame retardancy, Synergism, Colemanite, Halogen, Antimony oxide
https://hdl.handle.net/11511/33343
POLYMER DEGRADATION AND STABILITY
Department of Metallurgical and Materials Engineering, Article

Suggestions

Synergistic effect of boron containing substances on flame retardancy and thermal stability of intumescent polypropylene composites
Yılmaz, Ayşen; BAYRAMLI, ERDAL (2010-12-01)
The synergistic effect of four different boron containing substances, zinc borate (ZnB), borophosphate (BPO4), boron silicon containing preceramic oligomer (BSi) and lanthanum borate (LaB), were studied to improve the flame retardancy of a polypropylene (PP) intumescent system composed of ammonium polyphosphate (APP) and pentaerythritol (PER). The flame retardancy of PP composites was investigated by limiting oxygen index (LOI). UL-94 standard, thermogravimetric analysis (TGA) and cone calorimeter tests. Th...
Flame retardancy and mechanical properties of pet-based composites containing phosphorus and boron-based additives
Kilinc, Mert; ÇAKAL, GAYE ÖZGÜR; Bayram, Göknur; Eroglu, Inci; Özkar, Saim (2015-06-10)
Flame retardancy of poly(ethylene terephthalate), PET, was improved using different flame retardant additives such as triphenylphosphate, triphenylphosphine oxide, zinc borate, and boron phosphate (BP). Composites were prepared using a twin screw extruder and subsequently injection molded for characterization purposes. The flame retardancy of the composites was determined by the limiting oxygen index (LOI) test. Smoke emission during fire was also evaluated in terms of percent light transmittance. Thermal s...
Sol-gel synthesis of antibacterial silver-doped silica powders from sodium silicate (water glass)
Tufan, Evrim Özdem; Durucan, Caner; Department of Metallurgical and Materials Engineering (2013)
Sol-gel processing routes for the synthesis of antibacterial silver-doped silica (Ag-SiO2) powders from an inorganic precursor, sodium silicate (Na2SiO3, water glass), have been established. For the synthesis of SiO2 powders, two different processing approaches were used. In the first one (indirect synthesis), silver ions were incorporated into the immature wet silica gels obtained from sodium silicate by the exposure of the silica gels to aqueous silver nitrate (AgNO3) solutions. In the second one, silver ...
Synergistic effect of boron containing substances on flame retardancy and thermal stability of clay containing intumescent polypropylene nanoclay composites
Dogan, Mehmet; Bayramlı, Erdal (Wiley, 2011-12-01)
The functions of nanoclay and three different boron containing substances, zinc borate (ZnB), borophosphate (BPO(4)), and boron silicon containing preceramic oligomer (BSi), were studied to improve the flame retardancy of polypropylene (PP)-nanoclay-intumescent system composed of ammonium polyphosphate (APP) and pentaerythritol (PER). The flame retardancy of PP composites was investigated using limiting oxygen index (LOI), UL-94 standard, thermogravimetric analysis (TGA), and cone calorimeter.
LANTHANUM DOPED DICALCIUM PHOSPHATE MIXED WITH GRAPHENE OXIDE BONE CEMENTS AS A POTENTIAL MATERIAL IN BIOMEDICAL APPLICATIONS
Motameni, Ali; Evis, Zafer; -, -; Department of Engineering Sciences (2021-9-06)
In this thesis, mesoporous particles of β-tricalcium phosphate (βTCP, βCa3(PO4)2) and lanthanum (La) doped βTCP were synthesized by wet precipitation method attached with a microwave refluxing system. Pure dicalcium phosphate (DCP) and La modified dicalcium phosphate (La-DCP) bone cements were prepared based on acid/base reaction between βTCP (or La- βTCP) and monocalcium phosphate monohydrate (MCPM) in the presence of water. DCP bone cements were also mixed with 1.5-3.5wt.% of graphene oxide (GO). The obta...
Citation Formats
C. Kaynak, “Synergistic fire retardancy of colemanite, a natural hydrated calcium borate, in high-impact polystyrene containing brominated epoxy and antimony oxide,” POLYMER DEGRADATION AND STABILITY, pp. 798–807, 2011, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/33343.
METU IIS - Integrated Information Service open@metu.edu.tr