Halogenation phosphate

The carbon black generated by a fire from a rubber source increases the smoke density other products are highly toxic and often corrosive. The halogens, phosphates, borates, and their acids evolved during a fire corrode metals and electrical and electronic equipment. Hence many of the fire retardants described below cannot be used in situations where the toxic gases evolved will create their own hazards. In these cases inorganic hydroxides are used, at filler-type addition levels. Aluminium hydroxide and magnesium hydroxide are used as non-toxic fire retardant systems. 

An overview is provided of ongoing risk assessments on halogenated phosphate ester flame retardants in Europe. On the basis of the so-called second and fourth Priority lists on Existing Chemicals (Council Regulation No793/93) three chlorinated phosphate ester flame retardants are selected. The selection is based on their hazard profile, volume and use pattern. The three substances involved are TCPP, TDCP and TCEP (Antiblaze V6 from Albemarle is also involved but, due to confidentiality, is not discussed. An outline is provided from a European point of view on topics such as methodology of risk analyses, data-gaps and worst case approach, industry involvement, downstream participation and possible impact of final report on industry. 2 refs. 

Poisons for the nickel catalyst are sulfur, arsenic, chlorides or other halogens, phosphates, copper and lead. A 15 percent nickel catalyst is poisoned at 775°C if the gas contains as little as 0.005 percent (50 ppm) sulfur. 

International flammability standards, which can be achieved by the use of halogenated phosphate esters include... 

Halogenated phosphate esters (26) and many other types of flame retardants such as phosphorous-containing compounds including chlorine and/or bromine were extensively reviewed by Hilado (154). 

Other fire retardants used include aluminum hydrate, antimony oxide, and molybdenum compound. Halogenated phosphate esters used in polyurethane foams and bromine compounds used in polyolefin foams are not used in phenolic foams. Flame retardants are used mostly in powder form, and accordingly, their distribution conditions are dependent on their particle size and shape. 

Mn VSb- calcium halogen phosphates CadPO ).(Cl,F) 480 blue fluorescent lights... 

Flame resistance Phosphonium salts, organohalogens, w/wo Sb20j, halogenated phosphates, vinyl phosphonates, sulfamates... 

Firemaster . [Great Lakes] Halogenated phosphate esters fire retardants f[Pg.146]

Organophosphorus compounds (OPs) are utilized on a large scale as flame retarding agents and plasticizers in a variety of products, such as plastic materials, rubbers, varnishes, lubricants, hydraulic fluids, and other industrial applications. This family of chemicals consists of alkylated and arylated phosphate or phosphonate esters and related compounds such as phosphites, phosphines, and related dimeric forms as well as ionic forms (Figure 31.2). " The low volatility of phosphoric acid and derivatives makes it the preferred choice of the phosphorus based FRs. These FRs are most effective in polymers that char readily. Also halogenated phosphate esters, such as tris(l-chloroisopropyl) phosphate (TCPP), and tris(2-chloroethyl) phosphate (TCEP), are widely used. These combine the properties of both the halogen and the phosphorus compounds. 

Halogenated phosphates are also suitable for polyolefins. They are regularly combined with other halogenated compounds and with antimony trioxide. 

More usually, the plasticizer component of the formulation is replaced by flame-retardant plasticizers such as liquid chlorinated paraffins, acting as secondary plasticizers up to 30 per cent of the original plasticizer content. As an associate plasticizer, phosphoric esters are often used. The appropriate flame-retardance is achieved by adding 1 or 2 phr. of phosphorus to the compound. More rigid or more flexible cold-resistant products can be formulated with triaryl or trialkyl phosphates, respectively. Halogenated phosphates may also reduce the flammability of plasticized PVC. 

Nanoeomposites are an environmentally friendly alternative to some types of flame retardants, as they eontain no additional halogens, phosphates or aromaties above those eontained in the ehosen polymer resin. The silicate remains intact at very high temperatures. In addition, whereas many flame retardant compounds, particularly filler types, inerease the earbon monoxide and soot levels produeed during combustion, no similar increases have been observed with nanoeomposites flame retardants. 

Halogenated phosphate esters are also suitable for PS and PU foams and thermosetting resins. 

Phosphate Esters. The phosphate esters can be subdivided into halo-genated and non-halogenated versions. Halogenated phosphate esters are used almost exclusively in PUR foams. Rhodia (Antiblaze) and Akzo Nobel (Fyrol) are key suppUers. The non-halogenated phosphate esters are primarily aryl esters and are used in engineering plastics. They are widely used in lubricants and as plasticizers in PVC. Rhodia, GLCC, and Akzo Nobel are the key producers. 

R = ethylene diamine, diethylene triamine, triethylene tetramine, polyamidoamine, macrocyclic polyamine X = halogen, phosphate, sulphate, hydroxyl, 2-ethylhexoate n - whole or fractional number m = metal valency... 

Commercial chemical fibers are combustible in nature, and improved FR properties must be considered in actual application. Most FR additives contain bromine (Br), chlorine (Cl), phosphorus (P), antimony, or aluminum. Among them, commonly used additives are additive brominated hydrocarbons and reactive brominated hydrocarbons, nonhalogenated phosphate esters, halogenated phosphate esters, trioxide antimony oxide, pentoxide antimony oxide and sodium derivatives, chlorinated hydrocarbons like chlorinated paraffin, and chlorinated cycloaUphatics. Others include chlorinated or brominated compounds, fluorinated compounds, magnesium carbonate, magnesium hydroxide, melamine, molybdenum compounds, silicone polymer, and zinc borate. Sometimes, polymers are chemically modified, and N, P, Cl, fluorine (F), silicon (Si), and Br elements can be introduced into the polymer main chain [49]. 

Halogenated phosphate ester Formula Weight 416.5 Halogen Content 44.5% Phosphorus Content 7.5%... 

Halogenated phosphate ester Halogen Content 49.2% Phosphorus Content 6.5%... 

Halides, halogens, phosphates, sulfates, sulfites, thiosulfates... 

Poisons for the nickel catalyst are sulfur, arsenic, chlorides or other halogens, phosphates. and copper or lead. A 15 percent nickel catalyst is poisoned at 775°C, should the gas contain 0.005 percent sulfur. This is equivalent to reaction of all the nickel on the surface of the crystallites 1 micron in diameter. For lower operating temperatures, the amount required for poisoning is even lower. When using naphtha as a feedstock, 0.5 ppm of sulfur (w/w) in the naphtha is the maximum allowed concentration for operation at 775°C. 

Aromatic esters are more resistant. Resistance to microbial attack among phthalate plasticizers follows resistance to hydrolysis—that is, essentially to heat stability. Aliphatic phosphate plasticizers are similar in microbial resistance to phthalates aromatic and halogenated phosphates and chlorinated paraffin appear to be inedible. Usually, plasticizer choice is dictated by other factors, thus requiring use of biocides. 

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