Product Details

CasNo： 84-66-2

MF： C12H14O4

Appearance： liquid

Delivery Time： 15 days

Packing： 230kg/drum

Purity： 99%

1. Basic Information

• Synonyms: Phthalic acid diethyl ester; Ethyl phthalate; Benzene - 1,2 - dicarboxylic acid diethyl ester; Solvanol; Phthalol

• Molecular Formula: C??H??O?

• Molecular Weight: 222.24 g/mol

• CAS Registry Number: 84 - 66 - 2

• EINECS Registry Number: 201 - 550 - 6

2. Physical and Chemical Properties

2.1 Physical Properties

• Appearance: Clear, colorless to slightly yellowish oily liquid with a faint, pleasant aromatic odor.

• Melting Point: - 40.5 °C (lit.)

• Boiling Point: 298 - 299 °C (lit.) or approximately 302 °C at normal pressure.

• Density: 1.12 g/mL at 25 °C (lit.), which means it is denser than water.

• Vapor Density: 7.66 (vs air), indicating that its vapors are heavier than air.

• Vapor Pressure: 1 mmHg at 100 °C; it has a relatively low vapor pressure, which means it has low volatility at normal temperatures.

• Refractive Index: n??/D 1.502 (lit.), which is an important optical property for identification and quality control.

• Flash Point: > 230 °F (closed cup), equivalent to about 110 °C. This indicates that it is combustible but not highly flammable under normal conditions.

• Solubility: Practically insoluble in water (1 g/L at 20 °C), but miscible with ethanol, ethyl ether, and soluble in acetone, benzene, carbon tetrachloride, ketones, esters, and aromatic hydrocarbons. It is also partly miscible with aliphatic solvents.

• Specific Gravity: 1.118

• Color: APHA: ≤ 15, showing its high purity in terms of colorlessness.

• Odor: Water - white, oily liquid with a very slight, almost odorless characteristic, and a bitter taste.

• pH: 7 - 8 (20 °C in H?O), which is close to neutral.

• Viscosity: 11.53 mm²/s, which affects its flow behavior in various applications.

• Explosive Limit: 0.75% (lower explosive limit), with an auto - ignition temperature of 854 °F (about 456.7 °C).

2.2 Chemical Properties

• Diethyl phthalate is an ester. It reacts with acids to liberate heat along with the formation of alcohols and acids. For example, in the presence of strong acids, it can undergo hydrolysis to form phthalic acid and ethanol.

• Strong oxidizing acids may cause a vigorous reaction that is exothermic enough to potentially ignite the reaction products.

• It also reacts with caustic solutions, generating heat.

• When mixed with alkali metals and hydrides, flammable hydrogen gas can be generated.

• Diethyl phthalate is generally stable under normal storage and usage conditions but can decompose when exposed to high heat, emitting acrid smoke and irritating fumes.

• It is incompatible with strong oxidizers, strong acids, nitric acid, permanganates, and water. It can also attack some forms of plastics.

3. Production Methods

• Traditional Method: It is commonly produced by the reaction of phthalic anhydride with ethanol in the presence of concentrated sulfuric acid as a catalyst. The reaction can be represented by the following chemical equation:

Phthalic anhydride (C?H?O?) + 2 Ethanol (C?H?OH) \(\xrightarrow{H?SO?}\) Diethyl phthalate (C??H??O?) + H?O

• • In this process, phthalic anhydride is first dissolved in ethanol, and then a small amount of concentrated sulfuric acid is added. The mixture is heated under reflux for a certain period. After the reaction is complete, the product is neutralized with a base (such as sodium carbonate), washed with water to remove impurities, and then purified by distillation.

• Alternative Green Methods: Some research is being done on more environmentally friendly production methods. For example, enzymatic catalysis has been explored as an alternative to the traditional sulfuric acid - catalyzed process. Enzymes can catalyze the esterification reaction under milder conditions, reducing energy consumption and waste generation. Another approach is to use solid - acid catalysts, which can be easily separated from the reaction mixture and reused, minimizing catalyst - related waste.

4. Quality Specifications

• Purity: The purity of diethyl phthalate typically ranges from 98% to 99.5% in commercial products. High - purity grades can reach up to 99.9% or more for applications that require extremely low levels of impurities, such as in the pharmaceutical and high - end fragrance industries.

• Acidity: The acidity (expressed as the content of free phthalic acid, C?H?O?) should be ≤ 0.01% in high - quality products. This is important as high acidity can affect the performance and stability of products in which diethyl phthalate is used.

• Moisture Content: Moisture content is usually controlled to be ≤ 0.10% for industrial - grade products, and even lower (e.g., ≤ 0.05%) for applications sensitive to water, such as in some pharmaceutical and electronic applications. Excessive moisture can cause hydrolysis of the ester, reducing its quality and effectiveness.

• Color: The color of diethyl phthalate is usually specified in terms of APHA (American Public Health Association) color units. High - quality products should have an APHA value of ≤ 15 or ≤ 30, indicating a high degree of colorlessness.

• Related Substances: The content of related substances, such as unreacted phthalic anhydride, ethanol, and by - products from side reactions, is strictly controlled. For example, the content of phthalic anhydride should be below a certain limit (e.g., ≤ 0.05%) to ensure the quality and performance of diethyl phthalate.

5. Applications

5.1 In the Plastic and Rubber Industry

• Plasticizer: Diethyl phthalate is widely used as a plasticizer. It can increase the flexibility, plasticity, and durability of plastics. It has good compatibility with many resins, such as vinyl resin, cellulose acetate, cellulose acetate butyrate, polyvinyl acetate, nitrocellulose, ethyl cellulose, polymethyl methacrylate, polystyrene, polyvinyl butyral, and vinyl chloride - vinyl acetate copolymers. However, its relatively high volatility compared to some other plasticizers limits its use in applications where long - term stability and low - volatility are crucial. It is commonly used in products like plastic films (including photographic films, blister packaging films, and tapes), molded plastics (such as toothbrushes, automotive components, tool handles, and toys), and extruded articles.

• Solvent for Rubber Processing: It can also be used as a solvent in rubber processing. It helps in dissolving and blending various additives and polymers in rubber formulations, improving the processing properties and the final performance of rubber products.

5.2 In the Pharmaceutical Industry

• Pharmaceutical Excipient: Diethyl phthalate is used as a pharmaceutical excipient. For example, it can be used as a plasticizer in film coatings on tablets, beads, and granules at concentrations of 10 - 30% by weight of the polymer. This helps in improving the mechanical properties of the coating, making it more flexible and resistant to cracking during handling and storage.

• Solvent and Denaturant: It is used as an alcohol denaturant. In some cases, it can also be used as a solvent for certain drugs or in the formulation of liquid medications, especially those involving cellulose - based polymers.

5.3 In the Fragrance and Cosmetics Industry

• Perfume Fixative: In perfumery, diethyl phthalate is used as a perfume fixative at a concentration of 0.1 - 0.5% of the weight of the perfume. It helps to slow down the evaporation of volatile fragrance compounds, making the scent last longer.

• Solvent and Binder in Cosmetics: It is used as a solvent for various organic molecules in cosmetics. This property makes it useful in binding cosmetic additives and fragrances. It can be found in a wide range of cosmetic products, including bathing soaps, toiletries, after - shave lotions, and skin - care products. It has been reported as an ingredient in 67 cosmetic formulations.

5.4 In the Pesticide Industry

• Component in Insecticide Sprays and Mosquito Repellents: Diethyl phthalate is used as a component in insecticide sprays and mosquito repellents. Its presence can enhance the effectiveness of these products, either by acting as a solvent for the active ingredients or by contributing to the overall formulation's stability and performance.

5.5 In Other Industries

• Analytical Reagent and Gas Chromatography Stationary Phase: In analytical chemistry, it is used as an analytical reagent. It can also be used as a gas chromatography stationary solution, especially for the separation and analysis of aromatic compounds, unsaturated compounds, and various oxygen - containing compounds (such as alcohols, aldehydes, ketones, and esters). The stationary phase made of diethyl phthalate can selectively retain and separate these compounds based on their different affinities for the stationary phase.

• Diluent in Dental Impression Materials: It can be used as a diluent in polysulfide dental impression materials, helping to adjust the viscosity and flow properties of the material for better application in dental procedures.

6. Toxicity and Safety

• Toxicity: Diethyl phthalate is generally considered to have low toxicity. The oral LD?? (median lethal dose) in rats is 8600 mg/kg. However, it can still have some adverse effects on human health. Inhalation, ingestion, or skin absorption may cause harm. It can irritate the skin and eyes. Its vapors or mists can irritate the eyes, mucous membranes, and the upper respiratory tract. Prolonged or repeated exposure may lead to symptoms such as headache, dizziness, and nausea.

• Environmental Impact: In the environment, diethyl phthalate is likely to undergo biodegradation. However, due to its widespread use, there are concerns about its potential accumulation in the environment, especially in water bodies and soil. It can penetrate soil easily and may contaminate groundwater and nearby waterways.

• Safety Precautions: When handling diethyl phthalate, appropriate safety measures should be taken. Operators should wear personal protective equipment, including gloves, safety glasses, and appropriate clothing to prevent skin contact and eye exposure. Adequate ventilation should be provided in the working area to avoid inhalation of vapors. In case of accidental ingestion or exposure, immediate medical attention should be sought. Storage should be in a cool, well - ventilated place, away from heat, flames, and incompatible substances such as strong oxidizers, strong acids, and alkalies.

7. Packaging and Storage

• Packaging: Diethyl phthalate is usually packaged in 200 - liter steel drums or in intermediate bulk containers (IBCs) made of high - density polyethylene (HDPE) for larger quantities. For smaller quantities, it can be packaged in 25 - liter plastic or metal cans. The packaging materials are selected to be resistant to the chemical properties of diethyl phthalate to prevent leakage and ensure product quality during storage and transportation.

• Storage: It should be stored in a cool, dry, and well - ventilated warehouse. The storage temperature should be maintained below 30 °C to avoid excessive evaporation and potential degradation. It should be kept away from direct sunlight, heat sources, and ignition sources. As it is combustible, it should be stored away from areas where fires are likely to occur. Additionally, it should be stored separately from incompatible substances to prevent chemical reactions. Regular inspection of the storage area and packaging is recommended to ensure the integrity of the product.