Flame Retardants in Plastics

Flame retardants that are often nsed in polycarbonate/ABS plastics (such as in compnter indnstry) include nonhalogen triaryl phosphates, such as RDP [resorcinol bis (diphenyl phosphate)] and BDP [bisphenol A bis(diphenyl phosphate)]. As BDP has lower phosphorus content compared to that of RDP, more of it should be used to match the flammability performance of RDP. In one particular study using polycar-bonate-ABS alloy, 9% of RDP or 12.3% of BDP was employed and showed equal to each other and excellent flame retardant properties [8]. 

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The phosphonate esters, HP(=0(OR)2, of alkylated phenols are used extensively as lubricating-oil additives to control bearing corrosion and oxidation, and to impart antimst properties as stabilizers, as antioxidants (qv) and flame retardants in plastics, as specialty solvents, and as intermediates (see Corrosion AND corrosion control Heat stabilizers). 

Organophosphoms compounds, primarily phosphonic acids, are used as sequestrants, scale inhibitors, deflocculants, or ion-control agents in oil wells, cooling-tower waters, and boiler-feed waters. Organophosphates are also used as plasticizers and flame retardants in plastics and elastomers, which accounted for 22% of PCl consumed. Phosphites, in conjunction with Hquid mixed metals, such as calcium—zinc and barium—cadmium heat stabilizers, function as antioxidants and stabilizer adjutants. In 1992, such phosphoms-based chemicals amounted to slightly more than 6% of all such plastic additives and represented 8500 t of phosphoms. Because PVC production is expected to increase, the use of phosphoms additive should increase 3% aimually through 1999. 

J. Green, Flammability and Flame Retardants in Plastics, Rapra Review Report, Vol. 4 (6), Rapra Technology Ltd,... 

The PBDEs (decaBDE, octaBDE, and pentaBDE) and are used as flame retardants in plastics, electronic equipment, printed circuit boards, vehicles, furniture, textiles, carpets, and building materials. Global demand has increased rapidly since the 1970s with 70,000 tonnes produced in 2001. Their flame retardant activity relies on decomposition at high temperatures, leading to the release of bromine atoms. This slows the chemical reactions that drive 02-dependent fires. HBCDs are a flame retardant added to extruded and expanded polystyrene that is used as thermal insulation in buildings. 

Tris(2-chloroethyl) phosphate is used as a flame retardant in plastics, especially in flexible foams used in automobiles and furniture, and in rigid foams used for building insulation. No data on occupational exposure levels were available. Tris(2-chloroethyl) phosphate has been detected in drinking-water, river water, sea water and sediments in various parts of the world (IARC, 1990). 

Passive fire protection (flame retardants in plastics) is an important societal benefit. 

Bourbigot S, Le Bras M. Flame retardants. In Plastics Flammability Handbook, 3rd Edn. Troitzsch J, Ed. Hanser Munich, Germany, 2004 chap. 5, pp. 133-157. 

Bromine compounds are also used as fire retardants. These compounds are about twice as effective as chlorine compounds on a weight basis, so that significantly lower concentrations are needed. However, bromine compounds are higher in cost than chlorinated compounds and are generally less stable under exposure to heat and light (29). Those compounds containing aromatic bromine are significantly more stable to heat and hydrolysis than the aliphatic type. Examples are decabromodiphenyl oxide (DBDPO), tetrabromobisphenol and tetrabromobisphenol A. A pentabromodiphenyl oxide blend is available for urethane foams and polyesters (34). Aliphatic bromine-type additives are used as flame retardants in plastic foams (polyurethane and polystyrene (33). 

Neutral phosphonic acid esters are utilized as halogen-free flame retardants in plastics and textile fibers. 

Tetrabromobisphenol A (TBBPA) is primarily used as a reactive flame retardant in epoxy resin circuit boards. Both hydroxyl groups on TBBPA can be reacted with epichlorohydrin under basic conditions to form the diglycidyl ether, which is widely used in epoxy resin formulations. TBBPA is also used in polycarbonate and ether polyester resins and is used as a chemical intermediate for the synthesis of tetrabromobisphenol A allyl ether, -bis(2-hydroxyethyl ether), -carbonate oligomer, and -diglycidyl ether. TBBA is also used as a flame retardant in plastics, paper, and textiles, and as a plasticizer in adhesives and coatings. 

The final use of chemical products can result in the release of hazardous substances affecting man and the environment. Chemicals can be released from products used in the indoor environment, released to the atmosphere when a product is used outside, and released to groundwater if the chemicals leach out of a product in a landfill. Data are extremely limited on how many chemical products there are on the market today, on their chemical content, and on whether - and how - they may be releasing hazardous substances to the environment. Recent studies have shown that, in some cases, the majority of emissions released during the entire lifecycle occur during the service life of the product, rather than during production. A study conducted by TNO estimated that over 75 percent of total emissions to the environment from phthalates in plastics, brominated flame retardants in plastics, and zinc from tires occurred during the service life (TNO, 2001). 

BDE-154 is a component of the commercially available octa-BDE, which is a complex mixture consisting typically of 0.5% pentabromodiphenyl ether isomers, 12% hexabromodiphenyl ether isomers, -45% heptabromodiphenyl ether isomers, 33% octaBDE isomers, 10% nonabromodiphenyl ether isomers and 0.7% decabromodiphenyl ether. It is used as a flame retardant in plastics for electrical and electronic equipment. 

Use As fillers in rubber, paper, plastics, adhesives, polishes, inks, paints, cosmetics, and as a flame retarder in plastics. 

Use High-pressure lubricants, as flame retardants in plastics and textiles, as plasticizer for polyvinyl chloride in polyethylene sealants, and in detergents. 

MAJOR PRODUCT APPLICATIONS chemical intermediate in production of antimony pentoxide flame retardant in plastics, paints, textiles... 

The synthesis of 1,2/C-a/aphosphospholancs 127 is based on the reaction of the substituted 3-aminopropylphosphines with diaryl disulfides or with elemental bromine in the presence of triethylamine [171, 172] (Scheme 77). Furthermore, the cyclic P(III) compounds may be converted to the corresponding oxides 122 or sulfides 128, useful as lubricating oil antioxidants and flame retardants in plastics and textiles. 

Van Raamsdonk, G. W., Elementary Sulfur as Flame-Retardant in Plastic... 

XRF is used to measure the amounts of phosphoms-based flame retardants in textiles and the amount of antimony-based flame retardant in plastics. For textiles, a piece of fabric is cut into a square piece and stretched across a standard sample cup and held in place by the sample container ring. This results in a flat specimen for analysis. Phosphorus levels in the range of 0.3-3% P can be measured in a sample in as little as 60 s. Details of the method are available from SPECTRO Analytical Instruments (www.spectro-ai.com). 

Among antimony compounds are antimony hydride (stibine, a gas) which is the most deadly, followed by antimony sulfide (stibinite), which is used in modern times in camouflage paints (because it reflects IR), and the antimony oxide/lead oxide and carbonate mixture Naples yellow, was used as a pigment and paint as well as a flame retardant in plastics (PVC) for their use in car components, in televisions and so on, because it quenches the fire by reacting chemically with burning materials, although it was also accused of causing cot deaths (see Chapter 10). 

About 5 mg of antimony shows a strong diaphoretic action (induces sweating), while 50 mg or more acts as an emetic. There are rumours that Mozart s death was due to acute antimony tartarate poisoning. It is also known that several Victorian doctors used antimony to dispose quietly of their unwanted wives or relatives. Antimony trioxide is used as a flame retardant in plastics, while Antimony chloride is used as a catalyst and a colouring agent. 

Details A liquid, used as a flame retardant in plastics. 

Uses Hardening alloy for lead (solder, pewter, white metal, shotgun pellets) lead-antimony-tin alloys (battery plates, casting) lead-antimony alloys (battery plates, roofing, radiation protection, ammunition) bearing metal semiconductor technology pyrotechnics flame retardant in plastics cast iron ingred. type metal solder collapsible tubes and foil sheet and pipe... 

Uses Pigment in white and opaque glass, plastics, rubber, dyeing, paints, linoleum, leather, dental rubber fluorescent pigment in paints and plastics ingred. of lithopone fungicide anhydrous in x-ray screens, TV screens flotation depressant for sphalerite ores flame retardant in plastics, elastomers, textiles, paper depilatory agent in cosmetics in food-pkg. adhesives filler in food-contact rubber articles for repeated use colorant in food-contact polymers in lubricants for incidental food-contact use... 

Synonyms Alkanes, C6-18, chloro Chlorinated n-paraffin (C6-C18) n-Paraffin (C6-C18), chlorinated Empirical CeHisCI Properties M.w. 120.62 Uses Lubricant for PVC plasticizer curing agent flame retardant in plastics and textiles EP agent... 

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