Fire and flame retardants

Fire retardant are substances that are used to slow or stop the spread of fire or reduce its intensity. This is commonly accomplished by chemical reactions that reduce the flammability of fuels or delay their combustion. Fire retardants are commonly used in firefighting, where they may be applied aerially or from the ground. Chemical reactions in the flame can be interrupted by phosphorous halides such as PBr₃.

The term flame retardants subsume a diverse group of chemicals which are added to manufactured materials, such as plastics and textiles, and surface finishes and coatings. Flame retardants are activated by the presence of an ignition source and are intended to prevent or slow the further development of ignition by a variety of different physical and chemical methods. They may be added as a copolymer during the polymerization of a polymer, mixed with polymer at a molding or extrusion process or, in particular for textiles, applied as a topical finish. Mineral flame retardants are typically additive while organo-halogen and organo-phosphorus compounds can be either reactive or additive.

In general, fire retardants reduce the flammability of materials by either blocking the fire physically (cooling, formation of a protective layer, or dilution) or by initiating a chemical reaction that stops the fire.

Chemical reactions in the flame can be interrupted by fire retardants. Generally, these retardants are phosphorous halides such as PBr₃.

Flame retardants can be separated into several classes:

• Minerals such as Al(OH)₃ or Mg(OH)₂, various hydrates, red phosphorus, and boron compounds, mostly borates.
• Organohalogen compounds including organochlorines such as chlorendic acid derivatives and chlorinated paraffins, organobromines such as decabromodiphenyl ether, decabromodiphenyl ethane, polymeric brominated compounds such as brominated polystyrenes, brominated carbonate oligomers, brominated epoxy oligomers, tetrabromophthalic anyhydride, tetrabromobisphenol A, and hexabromocyclododecane.
• Organophosphorus compounds. This class includes organophosphates such as triphenyl phosphate, resorcinol bis(diphenylphosphate), bisphenol A diphenyl phosphate, and tricresyl phosphate. In one important class of flame retardants, compounds contain both phosphorus and a halogen. Such compounds include tris(2,3-dibromopropyl) phosphate (brominated tris) and chlorinated organophosphates.

Market

The production of halogenated flame retardants often involves bromine. Therefore, the market of halogenated flame retardants is thoroughly controlled by the bromine producers. There is only a hand full of players worldwide. The three market leaders control about 80% of the market.

GAB Neumann’s process equipment

The production of brominated flame retardants involves free bromine and generates hydrobromic acid. Impervious graphite tends to be oxidized by free bromine therefore the preferred use of silicon carbide heat exchangers to process Br₂ containing HBr vapors.

GAB Neumann provides silicon carbide plate heat exchangers, silicon carbide block heat exchangers and silicon carbide shell & tube heat exchangers to the brominated flame retardants producers.

Associated products:

Silicon carbide shell and tube heat exchangers

Silicon carbide block heat exchangers

Silicon carbide plate heat exchangers