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Ethyl Phosphate, which can be called Ethyl Phosphate in Turkish or more technically Ethyl Acid Phosphate, is a product in the group of acidic phosphate esters formed by phosphoric acid with ethanol. Commercial "Ethyl Phosphate" products are mostly offered as a mono- and diester mixture of monoethyl phosphate and diethyl hydrogen phosphate together.
A commercial mono- and diester Ethyl Phosphate mixture is identified by CAS No 37203-76-2 and EC No 253-391-7. TCI offers this product directly under the names "Ethyl Phosphate (Mono- and Di-Ester mixture)" and "Phosphoric Acid Ethyl Ester (Mono- and Di-Ester mixture)".
When determining the chemical identity of this product, care should be taken to use the expression "Ethyl Phosphate" alone. Because the same expression can be used for pure Monoethyl Phosphate in some sources, Triethyl Phosphate in some sources, and mono- and diester mixture in some sources.
Pure Monoethyl Phosphate, i.e. Ethyl Dihydrogen Phosphate, is a defined compound with CAS No 1623-14-9, EC No 216-603-9, molecular formula C₂H₇O₄P, and molecular weight of approximately 126.05 g/mol.
Diethyl Hydrogen Phosphate is the second acidic ethyl phosphate ester with CAS No 598-02-7, EC No 209-912-5, molecular formula C₄H₁₁O₄P, and molecular weight approximately 154.10 g/mol.
Commercial Ethyl Phosphate CAS No 37203-76-2 can be considered as a mixture of these two acidic phosphate esters. Therefore, it is not correct to give a single exact molecular formula or a single exact molecular weight for the commercial mixture.
The main chemical property of Ethyl Phosphate is that it still carries acidic P-OH groups in its phosphate ester structure. This gives the product an acidic character, strong interaction with metal and mineral surfaces, and the ability to form phosphate salts by neutralization.
Acidic phosphate esters are generally special phosphorus compounds that can be evaluated in surfactants, curing catalysts in synthetic resins, metal bonding aids, textile foam control agents, dispersants, lubricant additives, and corrosion inhibitor systems.
The short ethyl chain of Ethyl Phosphate creates higher polar character compared to long-chain alkyl acid phosphates. Therefore, the behavior of the product is not the same as that of 2-Ethylhexyl Phosphate, Lauryl Phosphate, or long-chain phosphate esters.
Commercial Ethyl Phosphate is usually clear liquid in appearance, ranging from colorless to light yellow. TCI and associated commercial sources describe CAS 37203-76-2 in liquid form.
Ethyl Phosphate may exhibit strong acidic and corrosive properties. In the TCI and Sigma-Aldrich safety information, the product is classified as a corrosive substance that can cause severe skin burns and severe eye damage.
For this reason, when purchasing Ethyl Phosphate, the mono-/diester ratio, acid value or neutralization equivalent of the product, water content, color, purity, density and TDS, SDS and COA documents of the relevant application should be evaluated together.
WHAT IS ETHYL PHOSPHATE?
Ethyl Phosphate is an acidic organophosphorus compound or compound mixture consisting of ethyl esters of phosphoric acid.
In commercial practice, the name "Ethyl Phosphate" is most often used for a mixture of esters of mono- and diethyl phosphoric acid.
The CAS number of the commercial mixture is 37203-76-2, the EC number is 253-391-7. TCI product designation: Ethyl Phosphate (Mono- and Di-Ester mixture).
The same product: Phosphoric Acid Ethyl Ester (Mono- and Di-Ester mixture).
The main chemical components of the mixture can be evaluated as Monoethyl Phosphate and Diethyl Hydrogen Phosphate. The structure of Monoethyl Phosphate can be shown as: C₂H₅-O-P(=O)(OH)₂.
Its chemical name is Ethyl Dihydrogen Phosphate. CAS No is 1623-14-9. Its molecular formula is C₂H₇O₄P.
Its molecular weight is approximately 126.05 g/mol. The structure of Diethyl Hydrogen Phosphate is: (C₂H₅O)₂-P(=O)-OH. CAS No is 598-02-7. Its molecular formula is C₄H₁₁O₄P. Its molecular weight is approximately 154.10 g/mol.
Since commercial Ethyl Phosphate can contain these two structures in different proportions, it should not be considered as a single molecule pure chemical.
Therefore, it may be technically misleading to give a single molecular formula for commercial CAS 37203-76-2.
The basic structure of the Ethyl Phosphate family of molecules is attached to the phosphorus atom: one phosphoryl oxygen, one or two ethoxy groups, and one or two acidic hydroxyl groups.
Monoester carries more free P-OH groups.
Diethyl ester, on the other hand, carries a single P-OH group. This difference affects the product's acidity, neutralization behavior, interaction with water, binding to metal surfaces, and salt-forming capacity.
If the monoester/dieester ratio in the commercial blend changes, product performance may also change.
Therefore, it should not be assumed that CAS No 37203-76-2 products from different manufacturers are directly equivalent to one-to-one.
Ethyl Phosphate and Triethyl Phosphate should not be confused specifically. Triethyl Phosphate: CAS No 78-40-0 Molecular formula C₆H₁₅O₄P
It is a fully esterified neutral phosphate ester with a molecular weight of approximately 182.15 g/mol.
Triethyl Phosphate has no free P-OH group.
For this reason, Ethyl Phosphate does not exhibit the same acidic behavior as a mono-/diester blend.
Triethyl Phosphate shows more neutral phosphate ester properties, while Ethyl Phosphate is an acidic phosphate ester.
This distinction is critical for purchasing and formulation.
COMMON PRODUCT AND CHEMICAL NAMES
Ethyl Phosphate
Ethyl Phosphate
Ethyl Acid Phosphate
Ethyl Acid Phosphate
Ethyl Phosphate Mono- and Di-Ester Mixture
Ethyl Phosphate Mono- and Diester Blend
Phosphoric Acid Ethyl Ester
Phosphoric Acid Ethyl Ester
Phosphoric Acid Ethyl Ester Mono- and Di-Ester Mixture
Phosphoric Acid Ethyl Ester Mono- and Diester Mixture
Ethyl Phosphoric Acid Ester
Ethyl Phosphoric Acid Ester
Monoethyl Phosphate / Diethyl Hydrogen Phosphate Mixture
Monoethyl Phosphate / Diethyl Hydrogen Phosphate Blend
Ethyl Acid Phosphate Ester
Acidic Ethyl Phosphate Ester
Acidic Ethyl Phosphate Ester
CAS 37203-76-2
EC 253-391-7
Not all of these names are at the same level of detail.
CAS No 37203-76-2 is used to describe a mixture of commercial mono- and diester Ethyl Phosphate.
Monoethyl Phosphate is not the same product on its own.
Monoethyl Phosphate:
CAS No 1623-14-9
It has a separate chemical identity.
Diethyl Hydrogen Phosphate:
CAS No: 598-02-7
It has a separate chemical identity.
Triethyl Phosphate:
CAS No 78-40-0
CAS NO, EC / EINECS NO AND CHEMICAL IDENTIFICATION
Product Name: Ethyl Phosphate
Turkish name: Ethyl Phosphate / Ethyl Acid Phosphate
Trade chemical description: Phosphoric Acid Ethyl Ester Mono- and Diester Mixture
CAS No: 37203-76-2
EC No: 253-391-7
Chemical class: Acidic alkyl phosphate esters
Main ingredient family: Monoethyl Phosphate + Diethyl Hydrogen Phosphate
Single molecular formula: Not defined
Single molecular weight: Not defined
Physical form: Liquid
Appearance: Clear liquid from colorless to light yellow
Basic chemical character: Acidic phosphate ester mixture
Transport class, TCI product: UN 1760
Hazard class: 8
Packing group: III
Monoethyl Phosphate:
Chemical Name: Ethyl Dihydrogen Phosphate
CAS No: 1623-14-9
EC No: 216-603-9
Molecular formula: C₂H₇O₄P
Molecular weight: Approximately 126.05 g/mol
Simplified structure: C₂H₅O-P(=O)(OH)₂
Diethyl Hydrogen Phosphate:
CAS No: 598-02-7
EC No: 209-912-5
Molecular formula: C₄H₁₁O₄P
Molecular weight: Approximately 154.10 g/mol
Simplified structure: (C₂H₅O)₂-P(=O)-OH
The physical and analytical properties of commercial Ethyl Phosphate may depend on the ratio of mono-/diester.
Therefore, it is not correct to transfer the physical properties of pure Monoethyl Phosphate directly to the commercial blend of CAS 37203-76-2.
Likewise, Diethyl Hydrogen Phosphate data should not be used as a general specification for the entire commercial mixture.
CHEMICAL STRUCTURE AND MOLECULAR PROPERTIES OF ETHYL PHOSPHATE
The basic chemical structure of Ethyl Phosphate is based on partially ethyl esterified derivatives of phosphoric acid.
Phosphoric acid:
H₃PO₄
It carries three acidic hydroxyl groups in its structure.
As a result of the esterification of one of these groups with ethanol, Monoethyl Phosphate is formed.
General structure:
C₂H₅O-P(=O)(OH)₂
is as follows.
Diethyl Hydrogen Phosphate is formed as a result of the conversion of two hydroxyl groups to ethyl ester.
General structure:
(C₂H₅O)₂-P(=O)-OH
is as follows.
Commercial Ethyl Phosphate is a mixture of these two acidic ester structures.
Monoester has higher acid functionality because it carries two acidic hydrogens.
Diester carries one acidic hydrogen.
Therefore, as the amount of monoester in the mixture increases, the total acid equivalent may change.
This situation:
The amount of neutralization,
interaction with metal ions,
salt formation,
Catalytic behavior
and surface properties
may affect.
P=O and P-OH bonds in the phosphate group form a high polar character.
Ethyl groups give the molecule a limited hydrophobic character.
However, since the ethyl chain is very short, Ethyl Phosphate is significantly more polar than long-chain alkyl phosphate esters.
For example, 2-Ethylhexyl Phosphate has a longer hydrocarbon chain, so it shows different compatibility with the oil phase.
Ethyl Phosphate, on the other hand, may interact more strongly in polar systems due to its small alkyl chain and acidic phosphate groups.
Free P-OH groups can be neutralized with bases.
For example, phosphate ester salts of alkali metals, amines, or other cations can be formed as a result of reaction with the appropriate base.
This neutralization can change the pH, solubility, surfactant behavior, adsorption to the metal surface and compatibility of the product with other formulation ingredients.
The interaction of Ethyl Phosphate with metal surfaces is one of the important properties of acidic phosphate esters.
The phosphate group can form strong polar interactions with metal oxide or hydroxide surfaces.
Therefore, acidic phosphate esters can be generally evaluated in metal bonding, surface treatment, and corrosion prevention formulations.
The main properties of Ethyl Phosphate at the molecular level are:
Phosphate ester group carry
Containing free acidic P-OH groups
Show high polarity
Neutralizing with bases
To be able to form phosphate ester salts
To be able to interact with metal and mineral surfaces
Showing high hydrophilic character due to its short ethyl chain
To be able to react as a chemical intermediate
To be able to exert an acidic catalytic effect
PHYSICAL AND CHEMICAL PROPERTIES OF ETHYL PHOSPHATE
Commercial Ethyl Phosphate CAS No 37203-76-2 is usually clear liquid that can range from colorless to light yellow.
General technical specifications:
Physical form: Liquid
Appearance: Clear liquid from colorless to light yellow
Chemical Grade: Acidic phosphate ester blend
CAS No: 37203-76-2
EC No: 253-391-7
Main ingredients: Monoethyl Phosphate and Diethyl Hydrogen Phosphate
Single molecular formula: Not defined
Single molecular weight: Not defined
Acidic character: Strong
Corrosive character: Can be found
Interaction with water: Depends on grade and mono-/diester ratio
Color: Depends on grade
Density: Grade dependent
Viscosity: Grade dependent
Acid value / neutralization equivalent: Grade dependent
Monoester ratio: Grade dependent
Diester ratio: Depends on grade
Amount of water: Depends on grade
Free phosphoric acid: May need to be checked according to product specification
TCI defines commercial Ethyl Phosphate as a mixture of mono- and diester and liquid.
Fisher Scientific lists the same TCI product as yellow liquid.
Other commercial batches can range from colorless to light yellow.
Therefore, color alone is not enough for product identification.
It is not correct to generalize a single density or single viscosity value to all Ethyl Phosphate products, as the physical properties of the commercial mixture may vary depending on the mono-/diester distribution and water content.
Exact manufacturer TDS and COA certificate should be used at the time of purchase.
HOW DOES ETHYL PHOSPHATE WORK AT THE MOLECULAR LEVEL?
The basic chemical behavior of Ethyl Phosphate is due to the acidic P-OH groups in the phosphate group.
These protons can undergo a neutralization reaction with suitable bases.
As a result of neutralization, organic phosphate salts are formed.
This reaction can be used to adjust the surfactant and solubility behavior of the product.
On metal surfaces, the polar character of the phosphate group plays an important role.
The metal surface often contains metal oxide or hydroxide groups.
The acidic phosphate ester group may exhibit adsorption or coordination type interactions with these surfaces.
Therefore, acidic phosphate esters can be useful in metal bonding and surface treatments.
The short ethyl chain of Ethyl Phosphate does not form a large hydrophobic layer on the surface.
In this respect, it differs from long-chain alkyl phosphates.
Therefore, when determining the usage area, it should not be assumed that all alkyl phosphate esters have the same surfactant properties.
Ethyl Phosphate also carries functional groups that can act as acidic catalysts.
Nippon Chemical Industrial shows acidic phosphate esters in its product line, which can be used as curing catalysts in synthetic resins.
In such applications, the acidic phosphate group can alter the rate of certain reactions in the resin system.
But the effect of the product:
Resin chemistry,
catalyst amount,
temperature,
Amount of water
and other contributions.
Ethyl Phosphate's role in lubricant systems can also be based on the interaction of the phosphate ester group with the metal surface.
Phosphorus-containing polar molecules can adsorb onto the metal surface, altering the surface behavior under boundary lubrication conditions.
Therefore, acidic phosphate esters can be considered among lubricant additives in general.
The main effects of Ethyl Phosphate at the formulation level are:
Providing acidic properties
Forming phosphate ester salts by neutralization
Interacting with metal surfaces
Supporting surface bonding
Providing acidic catalytic effect
Changing dispersion and surface behavior
Acting as a polar additive in lubricant formulations
To be used as a chemical intermediate
IN WHICH SECTORS IS ETHYL PHOSPHATE USED?
The use of Ethyl Phosphate should be evaluated according to the exact grade and mono-/diester ratio.
The major application areas reported for the acidic phosphate esters product family are:
Chemical synthesis
Production of chemical intermediates
Synthetic resin systems
Resin curing catalysts
Metal surface treatments
Metal clamping systems
Anti-corrosion formulations
Lubricant additives
Dispersing formulations
Surfactant systems
Textile processing aids
Foam control formulations
Fire extinguishing chemicals
Special additives for powder flowability
Nippon Chemical Industrial separately identifies Ethyl Acid Phosphate in its acidic phosphoric ester product family and offers this product family for applications such as surfactants, synthetic resin curing catalysts, metal bonding agents, textile defoamers, dispersants, lubricant additives and corrosion inhibitors.
However, it should not be assumed that all these uses are automatically appropriate for every grade of Ethyl Phosphate.
In particular, products sold by TCI and Sigma-Aldrich under CAS No 37203-76-2 are positioned for laboratory and chemical synthesis purposes.
Commercial industrial grade and manufacturer recommendations for industrial formulation application should be further verified.
SYNTHETIC RESIN AND CHEMICAL INTERMEDIATE APPLICATIONS OF ETHYL PHOSPHATE
Acidic phosphate esters can be used as catalytic auxiliaries in certain synthetic resin systems.
The free P-OH groups in Ethyl Phosphate provide acidic character.
This acidic nature can alter the rate of certain resin reactions or the curing behavior.
For this reason, the use of the product in the synthetic resin system should not be determined only by being a "phosphate ester".
The chemical structure of the resin is important.
Other catalysts used are important.
The amount of moisture is important.
Process temperature is important.
The amount of Ethyl Phosphate is important.
An overly acidic additive can lead to unwanted side reactions or corrosion in some systems.
Therefore, if it is to be used as a resin catalyst, small-scale curing screening should be performed.
Ethyl Phosphate can also be considered as a chemical intermediate in the production of other phosphate esters or phosphate salts.
Acidic P-OH groups:
With the Amen,
with alkaline bases,
with metal compounds
It can form salt under suitable conditions.
In this way, phosphate ester derivatives with different solubility and surfactant behavior can be obtained.
However, the exact usage conditions in the synthesis or production process of the product should be determined based on the process safety of the application and the manufacturer's technical information.
METAL SURFACE, CORROSION AND LUBRICANT APPLICATIONS OF ETHYL PHOSPHATE
One of the significant applications of acidic phosphate esters is their interaction with metal surfaces.
Phosphate groups can have a high affinity for metal oxide surfaces.
Therefore, Ethyl Phosphate can be considered as the polar additive that promotes bonding or surface adsorption in certain metal surface formulations.
Nippon Chemical Industrial positions acidic phosphate esters between metal bonding agents and corrosion inhibitors.
The anti-corrosion behavior does not depend solely on the phosphate group of the molecule.
The type of metal matters.
pH is important.
The amount of water is important.
The amount of electrolytes is important.
Other corrosion inhibitors are important.
Therefore, Ethyl Phosphate should not be assumed to be a corrosion inhibitor alone for a particular metal.
In lubricating applications, the polar phosphate group may interact with the metal surface.
This property can contribute to the formation of a surface film under boundary lubrication conditions.
However, Ethyl Phosphate is short ethyl chain and acidic product.
It should not be expected to have the same oil solubility or friction reduction performance as long-chain alkyl phosphate esters.
If the lubricant is planned to be used in formulation:
Base oil compatibility,
acid value,
metal corrosion,
presence of water,
High temperature behavior
and compatibility with other contributions
It should also be tested.
IS ETHYL PHOSPHATE USED IN FOOD, COSMETICS AND PHARMACEUTICAL APPLICATIONS?
CAS No 37203-76-2 Ethyl Phosphate mono-/diester mixture should be evaluated as a technical and laboratory chemical as standard.
It should not be used directly as a food additive.
It should not be assumed that it is a food type.
It should not be assumed that it is cosmetic grade.
It should not be assumed that it is pharmaceutical grade.
The TCI product is sold as a laboratory chemical.
The Sigma-Aldrich SDS specifies the defined area of use as laboratory chemicals and substance synthesis.
In the general product family of acidic phosphate esters, some manufacturers may mention pharmaceutical raw material applications.
However, this general application does not directly prove the pharmaceutical suitability of CAS No 37203-76-2 technical Ethyl Phosphate.
If pharmaceutical use is targeted:
Exact chemical composition,
purity,
GMP,
pharmacopoeia compliance,
Impurity profile
and manufacturer conformity certificates
It should also be verified.
The same approach applies to cosmetic or food contact applications.
INDUSTRIAL APPLICATIONS OF ETHYL PHOSPHATE
Ethyl Phosphate can be evaluated as an acidic phosphate ester and chemical intermediate in industry.
Its main technical functions are:
To be used as a source of acidic phosphate esters
Providing polar interaction with metal surfaces
Forming phosphate ester salts by neutralization
To be used as a catalytic aid in synthetic resin reactions
Acting as an intermediate in chemical syntheses
To be evaluated in the development of dispersive systems
Contributing to metal bonding formulations
Evaluation in anti-corrosion systems
To be used as a polar component in lubricant additive systems
The following parameters should be evaluated together in Ethyl Phosphate formulation:
Monoester/dieester ratio
Total acidity
Acid value
Neutralization equivalent
Amount of water
Free phosphoric acid
Color
Density
Viscosity
pH
Base used
Neutralization level
Metal type
Temperature
Other surfactants
Electrolyte level
Resin system
Base oil or solvent system
Corrosion behavior
Storage stability
TDS
SDS
COA
Changing the monoester/dieester ratio can alter the acid equivalent of the product.
Therefore, using the same amount of CAS No 37203-76-2 from two different suppliers in the formulation does not guarantee the same result.
The new product must be compared on a laboratory scale.
WHAT PROBLEMS CAN ETHYL PHOSPHATE HELP SOLVE?
Ethyl Phosphate can be especially useful in formulations where acidic phosphate functionality is required.
Phosphate ester acidity required in formulation
Ethyl Phosphate can provide acidic phosphate function thanks to its free P-OH groups.
Phosphate ester salt needs to be prepared
The acidic groups of the product can be neutralized with suitable bases, allowing the preparation of different salt systems.
Polar interaction with the metal surface is insufficient
The phosphate group can promote the surface bonding of the formulation by providing strong interaction with metal oxide surfaces.
Acidic catalytic additive is required in synthetic resin system
Its acidic phosphate ester structure can be considered as a curing catalyst in some resin systems.
Metal surface affinity is desired to be increased in lubricant formulation
The polar phosphate group can contribute to metal surface adsorption.
The long-chain phosphate ester remains too lipophilic
Ethyl Phosphate with short ethyl chain can be considered as a more polar alternative.
pH remains too low in formulation
In this case, the amount of Ethyl Phosphate or the degree of neutralization should be re-evaluated.
Corrosion increases in metal formulation
The amount of acidic product, neutralization level, and metal compatibility should be checked. Due to the acidity of Ethyl Phosphate, improper handling may increase metal attack.
There is a difference in performance between products despite the same CAS number
Quality parameters such as monoester/dieester ratio, water content and free phosphoric acid should be compared.
Not every surface or corrosion problem should be solved by changing the amount of Ethyl Phosphate alone.
The whole formulation should be evaluated together.
THINGS TO CONSIDER WHEN USING ETHYL PHOSPHATE
The most important issue in the use of Ethyl Phosphate is the correct determination of the product identity.
The following points should be evaluated during use:
CAS Number must be verified.
CAS 37203-76-2 should not be confused with CAS 1623-14-9.
Not to be confused with Triethyl Phosphate CAS 78-40-0.
The monoester/dieester structure must be verified.
Total acidity should be checked.
The acid value or neutralization equivalent should be checked.
The amount of water should be controlled.
Free phosphoric acid should be analyzed if required.
The color must be checked.
Density and viscosity should be checked.
Neutralization should be controlled.
Metal compatibility should be tested.
Corrosion behavior should be evaluated.
Heat generation must be considered during the reaction with bases.
The pH of the formulation should be measured.
TDS should be examined.
SDS should be examined.
Batch values must be verified via COA.
Ethyl Phosphate should not come into contact with bare hands as it may show corrosive character.
Appropriate chemical-resistant gloves, eye protection and, where necessary, face protection should be used when working with the concentrated product.
TCI and Sigma-Aldrich data state that the product can cause severe skin burns and eye damage.
INITIAL FORMULATION APPROACHES FOR ETHYL PHOSPHATE
The following examples are initial approaches designed to illustrate how Ethyl Phosphate can be screened in formulation evaluation. These are not verified commercial recipes or manufacturing instructions.
Since Ethyl Phosphate is corrosive acidic chemical, actual formulation studies should be conducted with appropriate laboratory safety procedures, SDS conditions, and controlled small-scale testing.
EXAMPLE 1: ETHYL PHOSPHATE METAL SURFACE COMPATIBILITY SCAN
Objective: To compare the effect of Ethyl Phosphate level on surface interaction and corrosion behavior on different metal surfaces.
Starting components:
Formulation A – Control (% by weight):
Deionized water (carrier liquid): 100.00%
Ethyl Phosphate (mono-/diester blend): 0.00%
Neutralizing ingredient: 0.00%
Total: 100.00%
Formulation B – Low level (% by weight):
Deionized water (carrier liquid): 99.90%
Ethyl Phosphate (mono-/diester blend): 0.10%
Neutralizing ingredient: 0.00%
Total: 100.00%
Formulation C – Intermediate level (% by weight):
Deionized water (carrier fluid): 99.75%
Ethyl Phosphate (mono-/diester blend): 0.25%
Neutralizing ingredient: 0.00%
Total: 100.00%
Formulation D – High level (% by weight):
Deionized water (carrier liquid): 99.50%
Ethyl Phosphate (mono-/diester blend): 0.50%
Neutralizing ingredient: 0.00%
Total: 100.00%
Metal samples: Not part of the formulation; the same alloy, surface preparation, and exposure conditions are used in all trials.
No neutralizing component is used in this initial screening. Thus, the effect of Ethyl Phosphate dose on metal compatibility in acidic environment is observed without additional base variables. Neutralization can be evaluated separately in subsequent trials. Due to the risk of metal corrosion and severe burns, trials should be conducted with appropriate protective equipment and controlled laboratory conditions.
Application approach:
Ethyl Phosphate-free control system is prepared.
Different levels of Ethyl Phosphate are compared.
The formulation pH is recorded.
The metal surface appearance is followed.
Mass change or appropriate corrosion measurement is made.
Surface wetting behavior is examined.
After storage, formulation stability is checked.
The range that provides acceptable metal compatibility with sufficient surface effect is determined.
EXAMPLE 2: ETHYL PHOSPHATE NEUTRALIZATION SCREENING
Purpose: To evaluate the effect of neutralization degree on solubility, pH, and formulation stability.
Starting components:
Formulation A – Unneutralized control (% wt):
Ethyl Phosphate (mono-/diester blend): 1.00%
Sodium hydroxide solution (contains 10% NaOH): 0.00%
Deionized water (carrier phase): 99.00%
Total: 100.00%
Formulation B – Low base level (% by weight):
Ethyl Phosphate (mono-/diester blend): 1.00%
Sodium hydroxide solution (contains 10% NaOH): 1.12%
Deionized water (carrier phase): 97.88%
Total: 100.00%
Formulation C – Medium base level (% by weight):
Ethyl Phosphate (mono-/diester blend): 1.00%
Sodium hydroxide solution (contains 10% NaOH): 2.24%
Deionized water (carrier phase): 96.76%
Total: 100.00%
Formulation D – High base level (% by weight):
Ethyl Phosphate (mono-/diester blend): 1.00%
Sodium hydroxide solution (contains 10% NaOH): 3.35%
Deionized water (carrier phase): 95.65%
Total: 100.00%
Calculation assumption: It has been accepted that Ethyl Phosphate contains 50% monoethyl phosphate and 50% diethyl hydrogen phosphate by weight, with two acidic protons of the monoester and one of the diester being neutralizable. In this case, for the full theoretical neutralization of 1.00 g of the mixture, approximately 0.447 g of pure NaOH, i.e. approximately 4.47 g of 10% NaOH solution is required. Trials B, C, and D are approximately 25%, 50%, and 75% theoretical equivalent doses, respectively, according to this assumption. These are not measured degrees of neutralization. The base dose must be recalculated by verifying the actual mono-/diester ratio, acid value, titration results, and target pH. The risk of exothermic reactions and splashes during the controlled addition of the base to the acid phase must be managed.
Application approach:
The control sample is prepared without neutralization.
Different levels of controlled neutralization are created.
pH is measured.
Appearance and clarity are recorded.
Precipitation or phase separation is followed.
Stability at low and high temperature is compared.
If metal compatibility is required, it is also tested.
The neutralization level suitable for the application is determined.
ALTERNATIVES AND COMPARISON OF ETHYL PHOSPHATE
When choosing an Ethyl Phosphate alternative, the degree of phosphate esterification, acidity, alkyl chain length and purpose of application should be evaluated together.
ETHYL PHOSPHATE AND MONOETHYL PHOSPHATE
Monoethyl Phosphate is the only defined compound.
CAS No is 1623-14-9.
Its molecular formula is C₂H₇O₄P.
It has one ethoxy and two P-OH groups in its structure.
Commercial CAS No 37203-76-2 Ethyl Phosphate is a mixture of mono- and diester.
Therefore, pure Monoethyl Phosphate and commercial Ethyl Phosphate are not the same product.
Pure monoester may have higher acid functionality.
One-to-one substitution should not be made.
ETHYL PHOSPHATE AND DIETHYL HYDROGEN PHOSPHATE
Diethyl Hydrogen Phosphate CAS No is 598-02-7.
Its molecular formula is C₄H₁₁O₄P.
Its molecular weight is approximately 154.10 g/mol.
It has two ethoxy groups and one acidic P-OH group in its structure.
Ethyl Phosphate CAS No 37203-76-2 is a mixture of monoester and diester together.
Using the diethyl component alone may alter the total acidity and polarity of the product.
Therefore, the two products are not directly equivalent.
ETHYL PHOSPHATE AND TRIETHYL PHOSPHATE
Triethyl Phosphate is the most frequently mixed product.
Triethyl Phosphate: CAS No 78-40-0
Molecular formula C₆H₁₅O₄P
It is a neutral phosphate ester with a molecular weight of approximately 182.15 g/mol.
All three P-OH groups in its structure have converted to ethyl ester.
Therefore, there is no free acidic P-OH group.
Ethyl Phosphate CAS No 37203-76-2 is an acidic mono-/diester mixture.
Applications of Triethyl Phosphate that are associated with its solvent, plasticizer, or flame retardant properties should not be transferred directly to Ethyl Phosphate.
These two products are chemically different.
ETHYL PHOSPHATE AND 2-ETHYLHEXYL PHOSPHATE
2-Ethylhexyl Phosphate is an acidic phosphate ester that carries a longer and hydrophobic alkyl chain.
Ethyl Phosphate is much more polar in character because it carries only two-carbon ethyl groups.
2-Ethylhexyl Phosphate can show higher compatibility with oil-phase or hydrophobic systems.
Ethyl Phosphate, on the other hand, may exhibit different solubility and surface behavior in more polar formulations.
The two products should not be used interchangeably at the same rate of use.
ETHYL PHOSPHATE AND PHOSPHORIC ACID
Phosphoric acid is a completely inorganic acid in H₃PO₄ structure.
Ethyl Phosphate is a partially ethyl esterified derivative of phosphoric acid.
The presence of ethyl groups alters the molecule's interaction with organic phases and its surface properties.
Phosphoric acid and Ethyl Phosphate do not have the same acid equivalent and the same metal surface behavior.
Therefore, it should not be directly replaced one-to-one for the sole purpose of pH or acidity.
QUALITY CONTROL AND PURCHASING CRITERIA FOR ETHYL PHOSPHATE
The most important issue when purchasing Ethyl Phosphate is the correct identification of the desired chemical product.
Recommended information to review before purchasing:
Full product name
CAS No
EC No
Verification of a mono-/diester mixture
Monoester ratio
Diester ratio
Total acidity
Acid value
Neutralization equivalent
Free phosphoric acid
Amount of water
Color
Outlook
Density
Viscosity
Purity
Metal impurities, if necessary
Phosphorus amount, if necessary
Storage conditions
Shelf life
Packaging
Batch number
Origin
TDS
SDS
COA
REACH information
CAS No 37203-76-2 should be verified.
Not to be confused with CAS No 1623-14-9.
Not to be confused with CAS No 598-02-7.
CAS No 78-40-0 should not be specifically confused with Triethyl Phosphate.
In commercial Ethyl Phosphate blends, the mono-/diester ratio can directly affect performance.
Therefore, it is not correct to consider only two products with the same CAS number as equivalent.
TDS shows general product features.
The COA shows the actual analysis values of the delivered batch.
SDS indicate safe handling and handling conditions.
These three documents should be evaluated together.
STORAGE AND HANDLING OF ETHYL PHOSPHATE
Storage: Ethyl Phosphate should be stored in tightly sealed packages with appropriate chemical resistance.
Moisture: The packaging should not be left unnecessarily open, as the amount of water in the product can affect the chemical and formulation behavior.
Bases: Uncontrolled contact with strong bases can lead to a neutralization reaction and heat release.
Metals: Corrosive acidic product, so the material compatibility of the storage tank and transfer equipment should be verified.
Heat: The manufacturer's recommended storage temperature should be used.
Sun: It should be protected from direct sunlight and unnecessary heat sources.
Contamination: Mixing with reactive bases, oxidizers, and incompatible chemicals should be avoided.
Packaging: Exact packaging material should be selected according to manufacturer SDS and technical recommendations.
FIFO: Batch and shelf life tracking should be applied.
TCI's CAS No 37203-76-2 product in terms of transportation:
UN 1760
Class 8
Packing group III
It is listed as.
This classification indicates that the product is transported as a corrosive liquid.
Actual shipment must be based on the current SDS transport information of the grade purchased.
ETHYL PHOSPHATE SAFETY INFORMATION
Ethyl Phosphate CAS No 37203-76-2 should be evaluated as a corrosive chemical.
H314 on the TCI product page:
"It causes severe skin burns and eye damage."
It is classified with the term danger.
Sigma-Aldrich also in his SDS:
Skin abrasion Category 1B
and
Serious eye damage Category 1
There are classifications.
Direct skin contact with concentrated Ethyl Phosphate should be avoided.
Appropriate chemical resistant gloves should be used.
Protective glasses should be used.
Face protection should be used if there is a risk of splashing.
Proper ventilation should be provided in the process where fog or steam may occur.
The product should not be swallowed.
In case of skin or eye contact, the immediate intervention specified in the current SDS should be applied.
Controlled processing is required as exothermic reaction can occur during neutralization with bases.
Unsuitable metal equipment can corrode.
Storage and transfer equipment material compatibility should be checked.
The product should not be discharged into the environment uncontrollably.
Waste and packaging disposal should be done according to local legislation and SDS instructions.
WHAT SHOULD BE CONSIDERED WHEN BUYING ETHYL PHOSPHATE?
When purchasing Ethyl Phosphate, first of all, it should be precisely stated which "Ethyl Phosphate" product is desired.
In this product group, name similarity can lead to serious purchasing errors.
In order request:
Ethyl Phosphate, mono- and diester mixture
CAS No: 37203-76-2
is safer to use together.
The following information should be clarified before purchasing:
Use sector
Final application
Requirement of CAS No 37203-76-2
Mono-/diester mix requirement
Monoester ratio
Diester ratio
Total acidity
Acid value
Neutralization equivalent
Free phosphoric acid limit
Water limit
Color requirement
Density
Viscosity
Purity
Manufacturer
Origin
Packaging
Estimated order quantity
TDS
SDS
COA
REACH documents
Current TDS and COA information if the existing product is to be replaced
The price of Ethyl Phosphate should not be evaluated only by its kilogram cost.
Two products with different monoester/dieester ratios can provide different acidity when used in the same amount.
This can alter the need for neutralization and formulation performance.
If the cheaper product contains more free phosphoric acid or water, metal compatibility and process stability may change.
Therefore, the actual comparison should be made through COA and application testing.
ETHYL PHOSPHATE SUPPLY FROM ATAMAN KIMYA
Ethyl Phosphate; It is a phosphoric acid ethyl ester product that can be evaluated in chemical synthesis, acidic phosphate ester systems, metal surface applications, corrosion inhibitor formulations, resin catalyst systems, lubricant additives and different technical chemical formulations.
Companies that want to get information about the supply of Ethyl Phosphate from Ataman Kimya can request information about product suitability, current supply conditions, packaging options and price offer by sharing their usage areas and technical needs.
The current stock status, manufacturer, origin, CAS number, mono-/diester ratio, acidity properties, water amount, packaging and other technical specifications of the product should be confirmed from Ataman Kimya before ordering.
Sharing the following information in the request for quotation facilitates the evaluation of the right Ethyl Phosphate product:
Use sector and end application
Requirement of CAS No 37203-76-2
Mono-/diester mix requirement
Target monoester/dieester ratio
Acid value or neutralization equivalent
Maximum amount of water
Color requirement
If there is a metal surface application, the type of metal
Resin system if resin application
If neutralization is to be applied, the type of base used
Estimated order quantity
Requested packing
Requested technical documents
TDS or COA information of the current Ethyl Phosphate product, if applicable
FREQUENTLY ASKED QUESTIONS ABOUT ETHYL PHOSPHATE
What is Ethyl Phosphate?
Ethyl Phosphate is an acidic phosphate ester product containing ethyl esters of phosphoric acid. Commercial CAS No 37203-76-2 product is usually a mixture of mono- and diester.
What is the Turkish name of Ethyl Phosphate?
It can be called Ethyl Phosphate or Ethyl Acid Phosphate.
What is the CAS number of Ethyl Phosphate?
For mono- and diester commercial blend, CAS No is 37203-76-2.
What is the EC number of Ethyl Phosphate?
For CAS No 37203-76-2, the EC No is 253-391-7.
Is Ethyl Phosphate a single molecule?
Commercial CAS No 37203-76-2 is not the only pure molecule as the product is a mixture of mono- and diester.
What is the molecular formula of Ethyl Phosphate?
The only definitive molecular formula for commercial mono-/diester mixture should not be given.
What is the formula of Monoethyl Phosphate?
C₂H₇O₄P.
What is the CAS number of Monoethyl Phosphate?
CAS No is 1623-14-9.
What is the molecular weight of Monoethyl Phosphate?
It is approximately 126.05 g/mol.
What is the formula of Diethyl Hydrogen Phosphate?
C₄H₁₁O₄P.
What is the CAS number of Diethyl Hydrogen Phosphate?
CAS No is 598-02-7.
What is the molecular weight of Diethyl Hydrogen Phosphate?
It is approximately 154.10 g/mol.
Is Ethyl Phosphate the same as Monoethyl Phosphate?
It is not always the same in commercial use. CAS No 37203-76-2 The product is a mixture of mono- and diester; pure Monoethyl Phosphate is CAS No 1623-14-9.
What is the CAS number of Triethyl Phosphate?
CAS No is 78-40-0.
What is the formula of Triethyl Phosphate?
C₆H₁₅O₄P.
Why is Ethyl Phosphate acidic?
It carries acidic protons because mono- and diester structures have non-esterified P-OH groups.
Why is Triethyl Phosphate not acidic in the same way?
In Triethyl Phosphate, all three hydroxyl groups of phosphoric acid have converted to ethyl ester and there is no free P-OH left.
Is Ethyl Phosphate a liquid?
The commercial CAS No 37203-76-2 product is offered as a liquid.
What is the color of Ethyl Phosphate?
The commercial product can usually be clear liquid from colorless to light yellow.
Is Ethyl Phosphate corrosive?
Yes. Commercial CAS No 37203-76-2 product is classified as corrosive due to the risk of severe skin burns and severe eye damage.
What is the UN number of Ethyl Phosphate?
It is given as UN 1760 for the TCI product.
What is the transport grade of Ethyl Phosphate?
For the TCI product, Class 8 is Packing Group III.
Can Ethyl Phosphate be used on metal surfaces?
Acidic phosphate esters can be evaluated in metal surface bonding and corrosion formulations. Exact use should be tested on the metal and formulation.
Is Ethyl Phosphate a corrosion inhibitor?
The acidic phosphate ester product family can be used in corrosion inhibitor formulations. However, Ethyl Phosphate alone should not be assumed to be a corrosion inhibitor for all metals.
Can Ethyl Phosphate be used in resins?
Acidic phosphate esters can be considered as curing catalysts in certain synthetic resin systems.
Can Ethyl Phosphate be used as a surfactant?
Acidic phosphate esters are a family of products that can be used in surfactant formulations. Due to the short ethyl chain of Ethyl Phosphate, its behavior differs from that of long-chain phosphate esters.
Is Ethyl Phosphate used in lubricants?
Acidic phosphate esters can be used as lubricant additives. Base oil compatibility and metal corrosion of Exact Ethyl Phosphate grade should be tested.
Is Ethyl Phosphate used in food?
CAS No 37203-76-2 standard technical product should not be considered as a direct food additive.
Is Ethyl Phosphate used in cosmetics?
Cosmetic suitability of the standard technical grade should not be assumed.
Is Ethyl Phosphate pharmaceutical grade?
The standard technical product should not be assumed to be pharmaceutical grade.
Does Ethyl Phosphate react with bases?
Acidic P-OH groups can be neutralized with suitable bases to form phosphate ester salts.
Why is the monoester to dieester ratio of Ethyl Phosphate important?
Since monoester and diester carry different numbers of acidic P-OH groups, the total acidity and neutralization behavior vary.
Do two Ethyl Phosphate products with the same CAS number give the same performance?
Not always. Properties such as the ratio of mono-/diester, water, and free phosphoric acid may differ.
ETHYL PHOSPHATE – TECHNICAL SUMMARY
Ethyl Phosphate is the product name that refers to partially ethyl esterified acidic phosphate esters of phosphoric acid.
Commercial Ethyl Phosphate is most often offered as a mono- and diester mixture containing Monoethyl Phosphate and Diethyl Hydrogen Phosphate.
This commercial mixture is identified by CAS No 37203-76-2 and EC No 253-391-7.
TCI offers the product directly under the name "Ethyl Phosphate (Mono- and Di-Ester mixture)".
The commercial mixture is not a single pure molecule.
Therefore, one definitive molecular formula or single definitive molecular weight should not be given.
Monoethyl Phosphate is a separate chemical.
It has CAS No 1623-14-9, EC No 216-603-9, molecular formula C₂H₇O₄P, and molecular weight of approximately 126.05 g/mol.
Diethyl Hydrogen Phosphate is a separate chemical.
It has CAS No 598-02-7, EC No 209-912-5, molecular formula C₄H₁₁O₄P, and molecular weight of approximately 154.10 g/mol.
Ethyl Phosphate and Triethyl Phosphate should not be confused with each other.
Triethyl Phosphate is a fully esterified neutral phosphate ester with CAS No 78-40-0 and the formula C₆H₁₅O₄P.
Ethyl Phosphate is an acidic mono-/diester system carrying free P-OH groups.
The acidic phosphate groups of Ethyl Phosphate can be neutralized by bases, have strong polar interaction with metal surfaces, and allow the preparation of different phosphate ester salts.
The acidic phosphate ester product family can be used in surfactants, resin curing catalysts, metal bonding aids, dispersants, lubricant additives and corrosion inhibitor formulations.
The exact industrial use suitability of CAS No 37203-76-2 Ethyl Phosphate should be verified based on the manufacturer's grade.
TCI and Sigma-Aldrich products are commercial examples for laboratory and chemical synthesis use.
Ethyl Phosphate exhibits corrosive character.
TCI and Sigma-Aldrich safety data report severe skin burns and severe eye damage classification.
The TCI product is given as UN 1760, Class 8 and Packaging Group III in terms of transportation.
When purchasing Ethyl Phosphate, CAS number, mono-/diester ratio, total acidity, acid value or neutralization equivalent, water, free phosphoric acid, color, density and viscosity should be evaluated together.
Companies planning to supply Ethyl Phosphate from Ataman Kimya should clearly state that they want the CAS No 37203-76-2 mono-/diester mixture; It is recommended that they confirm the current product and offer conditions by sharing the target application, acidity requirement, ester distribution, quantity, packaging and technical document needs.
