Halide flame retardants
Halide fire retardant is a kind of commonly-used organic fire retardants. The order of efficacy on fire retardancy for halogen element is I> Br> Cl> F. Because of that the C-F bond is very stable and is difficult to be broken down, so it has a poor fire-retardant effect. Moreover, owing to the poor thermal stability of the sulfonated, therefore, the industry usually applies chloride or bromide as the preferred fire retardant. The order of the fire-retardant effect of different kinds of organic compounds is that: aliphatic> cycloaliphatic> aromatic. However, the aliphatic compound has a poor thermal stability with the processing temperature should not exceed 205 ℃. In contrast, the thermal stability of the aromatic is relative good with the processing temperatures being up to 315 ℃. For the fire-retardant halide, they usually have relative high halogen content. Common halide fire retardants are as follows:
Chlorinated paraffin is made from the direct chlorination of wax. It has a good chemical stability with low cost and a relative wide application. It is often used in combination with antimony trioxide.
Full kelevan decane is generally produced by as following: first chloride the cyclopentadiene to yield hexachlorocyclopentadiene; then further go through dimerization under the catalysis of anhydrous aluminum chloride to obtain the final product.
Hexabromocyclododecane belongs cycloaliphatic class fire-retardant and is mainly applied to the fire retardancy in polypropylene, polystyrene and polypropylene fibers. It is made as following: first put butadiene for trimerization, to first make cyclododecyl-1, 5, 9-triene, and then further have addition reaction with bromine in the carbon tetrachloride solution to obtain the 1, 2, 5, 6, 9, 10-Hexabromocyclododecane.
Hexabromobenzene is produced from the bromination reaction of benzene with bromine in the tetrachloride solution with iron and sulfur as the catalyst. It is usually mixed with antimony trioxide.
The current applied brominates fire-retardants include mainly tetrabromoethane, tetrabromo phenol disulfide, decabromodiphenyl ether, decabromodiphenyl, isocyanate-tris (2,6-dibromopropyl) ester, 2, 2-[4-(2,3-dibromopropyl-3,5-dibromophenyl] propane, hexabromocyclododecane decane, hexabromobenzene, tetrabromobisphenol A, octabromodiphenyl ethers, tetrabromodiphenyl ether, poly-dibromo-phenylene oxide, bis (tribromophenoxy) ethane, tribromophenol, ethylene bis tetrabromophthalimide dicarboxamide, pentabromobenzyl polyacrylate and so on. They respectively can be applied to plate of integrated circuit, unsaturated polyester, epoxy resin, polystyrene resin, chloroprene rubber, styrene-butadiene rubber, natural rubber, polyester resins, polypropylene, polyethylene wires, polyurethane, fiber, ABS resin, nylon, polybutylene terephthalate and so on.
Put into the polystyrene (PS) (fire retardants), hexabromocyclododecane (fire retardants) and talc from the extruder into the feed section, and pump into the remaining foaming agent between the compression section and metering section to obtain a high compression-resistant foam sheet with a density of 34.7kg/m3 and water absorption of 0.09%.
Chemical Properties
It is white crystals and have two isomers with the melting point of low melting point type being 167-168 ℃ and high melting point type is 195-196 ℃. It has a good stability upon heat and ultraviolet light.
The above information is edited by the chemicalbook of Dai Xiongfeng.
Uses
1. It can be used in smoldering, for polystyrene foamed plastics, polypropylene and polyester, acrylic, polypropylene and other fabrics as smoldering finishing agent.
2. It is mainly used for thermoplastic and thermosetting polymers which have fire retardant requirements. It is particularly suitable for extrusion of foaming polystyrene.
3. It is used for the fire-retardant polystyrene of polypropylene plastics and fibers. It can also be used for the fire retardancy of finishing and leather double-sided coat after the fire-retardancy of polyester fabric. When used as additive fire retardants, it is especially suitable for polystyrene, unsaturated polyester, polycarbonate, polypropylene, synthetic rubber or the like.
Production method
First synthesize trans, trans, cis-cyclododecene triene (see also 10850): add butyl titanate and diethyl aluminum chloride together into benzene; further add butadiene at a temperature below 55 ℃ and make trans, trans, cis-cyclododecene-1,5,9-triene (C12H18, [2765-79-9]) through Tri-polymerization reaction. Then further obtain hexabromocyclododecane through bromination. To a 2000 L enameled pot reactor equipped with a reflux cooler and exhaust processing apparatus 2000L, add 1300 L of ethanol and 278 kg of trans, cis-ring two two-1, 5, 9-triene and 872 kg of bromine with the feed temperature being 15-25 ℃. During the entire process of adding materials, upon maintaining the presence of free bromine ion, the reaction color was red. After the reaction, remove the excess amount of bromine needle and have generated hexabromocyclododecane be subject to filtration, refinement to obtain 1000 kg of products with the yield being 91%. Another approach is applying aluminum chloride as the catalyst. To 800 parts of the Cyclododecyl-1, 5, 9-triene and 1500 parts of ethanol, add 150 parts of aluminum trichloride at 15-25 ℃m, followed by the addition of 2400 parts of bromine at 25-30 ℃ within 2h; Stir and have the reaction for 5 hour at room temperature and then filter. The filtered cake was washed by 200 parts of ethanol and 2% sodium bicarbonate to obtain hexabromocyclododecane with the yield being 86%. Moreover, the supplement of halogenated hydrocarbons to the ethanol can further inhibit the formation of resinous substance.
Chemical Properties
off-white to beige crystalline powder and chunks
Uses
1,2,5,6,9,10-Hexabromocyclododecane(HBCD) was used to compare the efficiency of different advanced extraction techniques for the recovery of brominated flame retardants from styrenic polymers. It was used to study the kinetics of the thermal and photolytic segregation of HBCD using HPLC.
Definition
ChEBI: 1,2,5,6,9,10-hexabromocyclododecane is a bromoalkane consisting of cyclododecane bearing six bromo substituents at positions 1, 2, 5, 6, 9 and 10. It has a role as a neurotoxin, a persistent organic pollutant and a xenobiotic. It is a bromoalkane, a bromohydrocarbon and a brominated flame retardant.
General Description
1,2,5,6,9,10-Hexabromocyclododecane(HBCD) is a brominated flame retardant. It is used in the textile industry and polystyrene foam manufacturing. Electrochemical reduction of HBCD at carbon and silver cathodes has been studied using cyclic voltammetry and controlled-potential electrolysis.
Biochem/physiol Actions
1,2,5,6,9,10-Hexabromocyclododecane enhances the diet-induced body weight gain and metabolic dysfunction via disruption of lipid and glucose homeostasis in mice fed normal diet or high-fat diet.
