Monoalkyl phosphate esters

The resulting product is a mixture of dialkyl and monoalkyl phosphate esters. These products also contain small amounts of condensed phosphates and phosphoric acid. Neutralization of the acids with bases like alkali hydroxides, ammonia, or amines produces water-soluble anionic surfactants and emulsifiers. 

Surfactants used in the polymerization are water-soluble, halogenated surfactants. They are in particular fluorinated surfactant such as ammonium, substituted ammonium, quarternary ammonium, or alkali metal salts of perfluorinated or partially fluorinated alkyl carboxylates, monoalkyl phosphate esters, alkyl ether or polyether carboxylates, alkyl sulfonates, and alkyl sulfates. 

Thomas, Gomes Colgate-Palmolive Light-duty liquid cleaning compositions containing monoalkyl phosphate ester Enhanced mildness to the human skin... 

The development of monoalkyl phosphate as a low-skin-irritating anionic surfactant is accented in a review with 30 references on monoalkyl phosphate salts, including surface-active properties, cutaneous effects, and applications to paste- and liquid-type skin cleansers, and also on phosphorylation reactions from the viewpoint of industrial production [26]. The preparation and industrial applications of phosphate esters as anionic surfactants were discussed [27]. 

In addition to their poor solubility in water, alkyl phosphate esters and dialkyl phosphate esters are further characterized by sensitivity to water hardness [37]. A review of the preparation, properties, and uses of surface-active anionic phosphate esters prepared by the reactions of alcohols or ethoxylates with tetra-phosphoric acid or P4O10 is given in Ref. 3. The surfactant properties of alkyl phosphates have been investigated [18,186-188]. The critical micelle concentration (CMC) of the monoalkyl ester salts is only moderate see Table 6 ... 

The development of monoalkyl phosphate as a low skin irritating anionic surfactant is accented in a review with 30 references on monoalkyl phosphate salts, including surface-active properties, cutaneous effects, and applications to paste and liquid-type skin cleansers, and also phosphorylation reactions from the viewpoint of industrial production [26]. Amine salts of acrylate ester polymers, which are physiologically acceptable and useful as surfactants, are prepared by transesterification of alkyl acrylate polymers with 4-morpholinethanol or the alkanolamines and fatty alcohols or alkoxylated alkylphenols, and neutralizing with carboxylic or phosphoric acid. The polymer salt was used as an emulsifying agent for oils and waxes [70]. Preparation of pharmaceutical liposomes with surfactants derived from phosphoric acid is described in [279]. Lipid bilayer vesicles comprise an anionic or zwitterionic surfactant which when dispersed in H20 at a temperature above the phase transition temperature is in a micellar phase and a second lipid which is a single-chain fatty acid, fatty acid ester, or fatty alcohol which is in an emulsion phase, and cholesterol or a derivative. 

Compound (1) phosphorylates phosphate monoesters and alcohols, although with the latter a considerable excess of alcohol is necessary to obtain satisfactory yields. In the absence of mercuric ions the milder phosphorylating species (3) can be isolated which converts monoalkyl phosphates to pyrophosphate diesters in good yield but does not react appreciably with alcohols unless catalytic amounts of boron trifluoride are added. Amine salts of (3) are converted to phosphoramidates on heating. In the presence of silver ions, O-esters of thiophosphoric acid behave as phosphorylating agents and a very mild and convenient procedure suitable for preparing labile unsymmetrical pyrophosphate diesters, such as the... 

C. Reactions.—The iV-chloroquinonimine (50) reacts with monoalkyl phosphates in dry pyridine to give symmetrical pyrophosphate esters. If present in excess it can react further, giving an intermediate which is attacked by alcohols or water with cleavage of the pyrophosphate bond. 

Monoalkyl phosphate and phosphate esters are special types of phosphoms-contain-ing anionic surfactants that are of great industrial importance. They are used for flameproofing, as antistatic for textiles, for foam inhibition, as an extreme pressure (EP) lubricant additive, as a surfactant component for alkaline, and as acid cleaners and for special cosmetic preparations (5). The commercially available phosphate ester products are complex mixtures of monoester and diester, free phosphoric acid, and free nonionic. 

Phosphate esters are prepared by the partial esterification of fatty alcohol with phosphorous oxychloride followed by hydrolysis (20). This method yields a product that is a mixture of monoalkyl, dialkyl, and trialkyl phosphates. 

Monoalkyl phosphates inhibit the foam generation of other anionic and nonionic surfactants. The composition of the phosphate ester greatly affects the functional properties of the product. 

Like other esters, phosphates undergo hydrolysis to the parent acid and alcohol. Here, the acidity of —OH attached to phosphorus has several effects. In the first place, since acidic phosphate esters can undergo ionization, there may be many species present in the hydrolysis solution. A monoalkyl ester, for example, could exist as dianion, monoanion, neutral ester, and protonated ester any or all of these could conceivably be undergoing hydrolysis. Actually, the situation is not quite that complicated. From the dissociation constants of these acidic esters, one can calculate the fraction of ester in each form in a given solution. The dependence of rate on acidity of the solution often shows which species is the principal reactant. 

Phosphorylation procedures using activated phosphate esters continue to be developed and esters of the type (3) may be conveniently prepared from monoalkyl phosphates and imidazole (or 2-hydroxypyridine) using bis-(2-pyridyl) disulphide and triphenylphosphine. -Nitrophenyl phosphate (4) and its symmetrical pyrophosphate (5) have been found to phosphorylate alcohols in the presence of pyridine and it is probable that... 

Basu, A.K. S. Dutta. Surfactant properties of monoalkyl ethanolamine phosphate esters./. Surface Sci. Technol. 2003, 19, 79—84. 

Trimetaphosphate esters can be obtained by heating the silver salt with an alkyl halide (5.319), or by heating a monoalkyl phosphate with excess dicyclohexyl carbodiimide. The ethyl ester hydrolyses instantly at 0°C to give diethyl triphosphate (5.320). 

Tris allyl phosphate, (CH2=CH-CH20)3P0, will give rise to a clear hard cross-linked polymer, although polymerised allyl or vinyl phosphates (12.75) have not generally led to successful commercial products. Simple monoalkyl phosphates on heating (12.76) can be made to yield polyphosphate esters with molecular weights approaching a million. 

Phosphate ester synthesis and properties have been reviewed earlier [1,10-13]. The current treatise will consequently concentrate on manufacturing techniques with special emphasis on recent advances in preparing high monoalkyl phosphate (MAP) and high dialkyl phosphate (DAP) esters. 

Monoalkyl phosphate and phosphate esters are special types of phosphorus-containing anionic surfactants that are of great industrial importance. They are used for... 

Trade Names Arlatone MAP Concentrate Potassium C12-13 alkyl phosphate Synonyms Potassium Cl 2-13 monoalkyl phosphate Definition Potassium salt of a complex mixture of esters of phosphoric acid and Cl 2-13 alcohols... 

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