Inorganic flame retardants

Catalysts Cleaners Little or no">v Petrochemicals f R D activity for J V bi ch applicatiojt/ Flame retardants Inorganic Lube oil Explosives chemicals Inks additives Ceramics 1 1 ... 

PBBs and PBDEs belong to a group of brominated organic compounds which are used as flame retardants. Flame retardants are valued for their ability to inhibit combustion in plastics, textiles, electric, and other materials. There are different groups of flame retardants inorganic and organic chemicals. Usually they are divided into reactive and additive flame retardants. 

Flame retardant (1947) n. A material that reduces the tendency of plastics to burn. Flame retardants are usually incorporated as additives during compounding, but sometimes applied to surfaces of finished articles. Some plasticizers, particularly the phosphate esters and chlorinated paraffins, also serve as flame retardants. Inorganic flame retardants include antimony trioxide, hydrated alumina, monoammonium phosphate, dicyandiamide, zinc borate, boric acid, and ammonium sulfamate. Another... 

Other flame retardants Inorganic phosphorus Ammonium polyphosphate Red phosphorus Melamines Melamine crystal Melamine cyanurate Melamine phosphates Magnesium hydroxide Molybdeniun compoimds Zinc borate... 

The subject of rubber as a filler is dealt with in the entry entitled Surface-modified rubber particles for pol)nirethanes. Hydrated alumina, otherwise known as alumina trihydrate (ATH), is considered under the heading Flame retardants inorganic oxide and hydroxide systems. Some mechanical property considerations are dealt with in the entry entitled Fillers their effect on the failure modes of plastics. ... 

Flame retardants inorganic oxide and hydroxide systems Flame retardants intumescent systems ... 

Boron compounds such as borax and boric acid are well known fire retardants for cellulosic products [1]. However, the use of boron compounds such as zinc borate, ammonium pentaborate, boric oxide, and other metallo-borates in the plastics industry has become prominent only since the late 1970s. This entry will review the manufacturing, chemical and physical properties, end-use applications, as well as modes of action of major boron compounds as fire retardants in polymers. The subject is also mentioned in the section entitled Flame retardants inorganic oxide and hydroxide systems. ... 

First there are additives which act to remove heat by endothermic decomposition and/or the generation of copious quantities of inert gases to dilute the combustible polymer degradation products. Materials such as alumina trihydrate (ATH) and magnesium hydroxide, which in toimage terms are by far the most widely used halogen-free flame retardants, work in this way. These additives are more fully described in the section Flame retardants inorganic oxide and hydroxide systems. ... 

Flame Retardant n (1947) A material that reduces the tendency of plastics to burn. Flame retardants are usually incorporated as additives during compounding, but sometimes applied to surfaces of finished articles. Some plasticizers, particularly the phosphate esters and chlorinated paraffins, also serve as flame retardants. Inorganic flame retardants include antimony trioxide, hydrated alumina, monoammonium phosphate, dicyandiamide, zinc borate, boric acid, and ammonium sulfamate. Another group, called reactive-type flame retardants, includes bromine-containing polyols, Chlorendic acid and anhydride, tetrabromo- and tetrachlorophthalic anhydride, tetrabromo bisphenol A, diallyl chlorendate, and unsaturated phosphonated chlorophenols. A few neat resins, such as PVC and the fluoro- and chlorofluo-rocarbons, are flame-retardant (Elias, H (2003) An introduction to plastics. Wiley, New York Modem plastics encyclopedia. McGraw-Hill/Modem Plastics, New York, 1986 1990, 1992, 1993 editions). See Flammability. 

FLAMERETARDANTS - ANTIMONYAND OTHER INORGANIC FLAME RETARDANTS] (Vol 10)... 

Antimony and other inorganic flame retardants, Halogenated flame retardants,... 

Flame letaidancy can be impaited to plastics by incorporating elements such as bromine, chlorine, antimony, tin, molybdenum, phosphoms, aluminum, and magnesium, either duriag the manufacture or when the plastics are compounded iato some useful product. Phosphoms, bromine, and chlorine are usually iacorporated as some organic compound. The other inorganic flame retardants are discussed hereia. 

Addition of approximately 40% of the halogen flame retardants are needed to obtain a reasonable degree of flame retardancy. This usually adversely affects the properties of the plastic. The efficiency of the halogens is enhanced by the addition of inorganic flame retardants, resulting ia the overall reduction of flame-retardant additive package and minimising the adverse effects of the retardants. 

Poly(vinyl chloride). PVC is a hard, brittle polymer that is self-extinguishing. In order to make PVC useful and more pHable, plasticizers (qv) are added. More often than not the plasticizers are flammable and make the formulation less flame resistant. Flammability increases as the plasticizer is increased and the relative amount of chlorine decreased, as shown in Table 7. The flame resistance of the poly(vinyl chloride) can be increased by the addition of an inorganic flame-retardant synergist. 

Molybdenum Oxide. Molybdenum compounds incorporated into flexible PVC not only increase flame resistance, but also decrease smoke evolution. In Table 10 the effect of molybdenum oxide on the oxygen index of a flexible PVC containing 50 parts of a plasticizer is compared with antimony oxide. Antimony oxide is the superior synergist for flame retardancy but has Httle or no effect on smoke evolution. However, combinations of molybdenum oxide and antimony oxide may be used to reduce the total inorganic flame-retardant additive package, and obtain improved flame resistance and reduced smoke. 

Inert Gas Dilution. Inert gas dilution involves the use of additives that produce large volumes of noncombustible gases when the polymer is decomposed. These gases dilute the oxygen supply to the flame or dilute the fuel concentration below the flammability limit. Metal hydroxides, metal carbonates, and some nitrogen-producing compounds function in this way as flame retardants (see Flame retardants, antimony and other inorganic compounds). 

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