Alkyl aryl phosphate

T. W. Lapp, The Manufacture and Use of Selected Aryl and Alkyl Aryl Phosphate Esters, Report NTIS PB-251678, Midwest Research Institute, Feb. 1976. 

Before the 1960s, products were introduced based on alkyl aryl phosphates that could contain chlorinated aromatic hydrocarbons. Such products have now entirely disappeared from commercial use, and the vast majority of the industrial organophosphate esters are based on triaryl phosphates with no halogenated components (Marino 1992). However, at older waste disposal sites, hydraulic fluid site contaminants could contain chlorinated hydrocarbons. As with the PCBs formerly included as additives in other forms... 

The synthesis of organophosphate ester compounds dates to the mid-1800s. From an early date, the most commercially useful compounds for lubricants, plasticizers, and hydraulic fluids were in the chemical family of the tertiary esters. Before 1970, products were introduced based on alkyl aryl phosphates that... 

PVC-FR (triaryl phosphate) flexible-5 (FOI 34 %) PVC-FR (alkyl aryl phosphate) flexible-6 (FOI 28 %) PVC rigid-1... 

Polyvinyl Chloride (PVQ Foams. Rigid PVC foam is inherently fire retardant because of the high chlorine content (56.7%). Flexible PVC foams present increased fire hazards because of the plasticizers they contain. Flammable plasticizers used include alkyl phthalates, as dioctyl phthalate. Non-burning types include alkyl aryl phosphates (phosphate esters). The latter types should improve resistance to ignition and reduce flame spread when compared to the usual phthalate plasticizers (38) (41). 

Phosphate esters are also used as hydraulic fluids in civil aircraft where thermal stability is less important than their low-temperature viscosities and cold flow properties. Trialkyl and alkyl-aryl phosphates are used which, when formulated with a VI improver, give fluids with pour points of -55 to -65°C and a VI of 170-300. They are also chosen for other low-temperature applications for conditions such as those found on North Sea, and similar weather condition, oil rigs. 

Figure 14. Thermal degradation of an alkyl aryl phosphate.

The mechanism of burning for polymers is believed to take place through thermal pyrolysis of the solid plastic to produce gases that act as fuel for the fire (45). Fire retardants work in both the condensed and the vapor phase to interrupt melting of the polymer and burning of the gases. Triaryl phosphates function well in the vapor phase. Alkyl aryl phosphates are believed to decompose in the flame front to form polyphosphoric acid, which stays in the condensed phase to form char, which reduces flammability and smoke evolution (46. 47). 

Isodecyl diphenyl phosphate Alkyl aryl phosphate... 

PVC Alkyl /aryl phosphates Flame retardant flexible compounds... 

Various product forms may occur during storage (typical for fatty acid derivatives) or production. DSC has been used for detection of polymorphism of butylated hydroxyanisole (BHA) [91]. Similarly, DSC has allowed to detect various product forms of the hindered phenolic antioxidant octade-cyl 3-(3, 5 -di-f-butyl-4 -hydroxyphenyl) propionate (Anox PP 18), which caused handling problems during production [92]. The DSC method for purity determination as used for curatives, such as 2,2 -benzothiazyldisulfide (MBTS) [93], and for sulfur and accelerators [79], is also applicable to other additives, such as antioxidants and antiozonants. DSC and TGA have been used to establish the oxidation and weight loss characteristics of commercially available triaryl, trialkyl and alkyl-aryl phosphate esters, which are widely used as plasticisers and flame retardants in the polymer industry [94]. 

DSC has been used to measure T on a variety of polymers including naphthalate copolymers [111,112], polyethylene terephthalate-5-nitrosophthalic acid copolymers [113], propene-pentene copolymers [114], 4-hydroxy benzoic acid-2-hydroxy-6-naphthoic acid copolymers [115], fluorinated perfluorocyclo butylenes [116], PET [117], polythioether ether ketones [14,104], polyvanillylidiene, alkyl/aryl phosphate esters [118], poly(L-lactic acid-poly(e-caprolactone) [119], benzylated waste pulp-L-lactic acid copolymers [120], PET - poly-1,4 butylene succinate [121], polyarylate-polytrimethylene terephthalate [122], polyimines [77], PVOH [123, 124], various Nylons [125]. 

Chloromethyl-4-nitrophenol has been described as a protecting group for alkyl or aryl phosphates [10]. Upon treatment with pyridine, the group is activated to form a phos-phorylating agent, and dialkyl or alkyl aryl phosphate esters may be obtained on reaction with the appropriate alcohol or phenol (Fig. 6.4). 

Santiclzer 2148 la a low-smoke, flame-retardant alkyl aryl phosphate ester plasticizer with very low volatility, excellent low-temperature performance and good softening efficiency. Molecular Weight Proprietary Phosphorus, % Proprietary Acidity (meq/100 gm max) 0.20 Appearance Clear, oily liquid Color (APHA) (Max) 200 Moisture (KF in Methanol) % max 0.10 Odor Essentially odorless Refractive Index ( 25C) 1.494-1.502 Specific Gravity (25/25C) 1.028-1.044 Density ( 25C) ca Ibs/gal 8.65 Crystallizing Point OC (32F)... 

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