Flame retarding agents

About 80-90% of the elemental P produced is reoxidized to (pure) phosphoric acid (p. 521). The rest is used to make phosphorus oxides (p. 503). sulfides (p. 506), phosphorus chlorides and oxochloride (p. 4%). and organic P compounds. A small amount is convened to red phos rftorus (see below) for use in the striking surface of matches for pyrotechnics and as a flame retarding agent (in polyamides). Bulk price for P4 is S2.00/kg. 

Polycarbonates. Polycarbonates (qv) are pardy crystalline thermoplastics with some disorder in the crystalline part and considerable order in the amorphous part. This disorder conveys high impact strength which, combined with its good transparency and outdoor exposure resistance, makes polycarbonates useful for vandal-resistant glazing and outdoor lighting. It is easily processed by extrusion and injection molding. Various uv and flame-retardant agents are often added. 

The preparation of flame-retardunt epoxy resins is accompanied by inclusion of telrahroinohisphenol A in the advancement process See also Flame-Retarding Agents. Products containing ca 20 wt % Br are extensively employed in the printed circuit board industry. 

In this paper we report the use of some phosphine oxides, phosphonic acids, and phosphinic acids to impart fire retardant properties to polymers. In addition, we postulate a mechanism by which these compounds behave as flame retardant agents. 

Tetrakishydroxymethyl phosphonium chloride (THPC) is well established as a flame retardant agent with textiles (3). Collins (2) has suggested that THPC and urea break down to produce phosphoric acid via a phosphine oxide, phosphinic acid, and phosphonic acid. For cellulose, Collins concludes flameproofing is essentially caused by the dehydrating action of the phosphoric acid formed. 

Flame retardants for polymers can also be classified as reactive (the flame-retarding agent reacts chemically with the polymer to become an integral part of the molecule) or additive (nonreactive agents that are simply blended or mixed into the compound). Flame retardants can also be classified by their major chemical group, as shown in Table 9.14. 

In the case of flame retardant silicone elastomer, many ingredients such as silica, platinum, and other flame retardant agents are incorporated into the base siloxane polymer. But there is no need to use the halogenated flame retardant agent, for example, bromine or chlorine compounds. This difference is an advantage of silicones compared with other synthetic polymers in terms of health and safety. 

Use Flame-retarding agent for cotton fabrics. May be used in combination with triethylolamine and urea (Roxel process) or with triethanolamine and tris(l-aziridinyl) phosphine oxide. 

Use Primary plasticizer for most resins and elastomers, floor finishes and waxes, flame-retarding agent. 

To date flame-retarding agents have not consciously been used for pharmaceutical products, and are not covered here, except to note that electrical or electronic equipment involved in drug administration normally has to use flame-resistant materials for safety purposes. 

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. 

Products and Uses A flame-retarding agent for textiles and canvas materials. Used for fireproofing. 

Details Solids, used as flame retarding agents in plastics until 1977, after which it was... 

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