Trixylyl phosphate

In volume terms the most important class of fire retardants are the phosphates. Tritolyl phosphate and trixylyl phosphate are widely used plasticisers which more or less maintain the fire-retarding characteristics of PVC (unlike the phthalates, which reduce the flame resistance of PVC products). Better results are, however, sometimes obtained using halophosphates such as tri(chloroethyl) phosphate, particularly when used in conjunction with antimony oxide, triphenyl stibine or antimony oxychloride. 

Characteristic Tricresyl phosphate Trixylyl phosphate Cresyl diphenyl phosphate Triphenyl phosphate... 

Organophosphate Ester Hydraulic Fluids. Organophosphate esters are made by condensing an alcohol (aryl or alkyl) with phosphorus oxychloride in the presence of a metal catalyst (Muir 1984) to produce trialkyl, tri(alkyl/aryl), or triaryl phosphates. For the aryl phosphates, phenol or mixtures of alkylated phenols (e.g., isobutylated phenol, a mixture of several /-butylphenols) are used as the starting alcohols to produce potentially very complex mixtures of organophosphate esters. Some phosphate esters (e.g., tricresyl and trixylyl phosphates) are made from phenolic mixtures such as cresylic acid, which is a complex mixture of many phenolic compounds. The composition of these phenols varies with the source of the cresylic acid, as does the resultant phosphate ester. The phosphate esters manufactured from alkylated phenylated phenols are expected to have less batch-to-batch variations than the cresylic acid derived phosphate esters. The differences in physical properties between different manufacturers of the same phosphate ester are expected to be larger than batch-to-batch variations within one manufacturer. 

Plasticizers include tricresyl phosphate and trixylyl phosphate. Foaming agents can be added in the case of using the polymers for wires, which require low dielectric constant and low dielectric loss tangent, such as communication cables, coaxial cables for computers and high-frequency cables. 

Figure 11 indicates the differences between three different chemical types of plasticizers. A comparison has been made between a commercial trixylyl phosphate (TXP), diisooctyl phthalate (DiOP) and diisooctyl sebacate (DiOS). It is apparent that all three points increase from TXP to DiOP to DiOS. The DiOS is at 50 p.h.r. since at 75 p.h.r. the film would be very low in tensile strength. 

TRIXYLYL PHOSPHATE (25155-23-1) Combustible liquid. May react violently with strong oxidizers, antimony(V) pentafluoride. Incompatible with lead diacetate, magnesium, silver nitrate, sulfuric acid, nitric acid, nitrates. 

Phosphate plasticizers such as tritolyl phosphate and trixylyl phosphate are generally used where good flame resistance is required, such as in insulation and mine belting. These materials, however, are toxic and give products with poor low-temperature resistance, i.e., with a high cold flex temperature (typically, -5°C). 

Synonyms Dimethylphenol phosphate (3 1) Tri (dimethylphenyO phosphate Trixylyl phosphate Xylenol, phosphate (3 1) Xylyl phosphate Empirical C24H2704P Formula [(CHs)2C6HsO]sPO... 

Trixylyl phosphate. See Trixylenyl phosphate Trizinc bis (orthophosphate). See Zinc phosphate... 

In certain apphcations, flame resistance can be important. In this case, flame retarders may he added. They act hy one of four possible mechanisms. They may act to chemically interfere with the propagation of flame, react or decompose to absorb heaL form a fire resistant coating on the polymer, or produce gases that reduce the supply of air. Phosphates are an important class of flame retarders. Tritolyl phosphate and trixylyl phosphate are often used in PVC. Halogenated compounds such as chlorinated paraffins may also be used. Antimony oxide is often used in conjunction to obtain better results. Other flame retarders include titanium dioxide, zinc oxide, zinc borate, and red phosphorus. As with other additives, the proper selection of a flame retarder will depend on the particular thermoplastic. 

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