Dimethyl phthalate Dimethyl phthalate

Structural formula

• Numbering system
• Physical property data
• Toxicological data
• Ecological data
• Molecular structure data
• Computing chemical data
• More
  • Properties and Stability
  • Storage method
  • Synthesis method
  • Purpose

Numbering system

CAS number:131-11-3

MDL number:MFCD00008425

EINECS number:205-011-6

RTECS number:TI1575000

BRN number:1911460

PubChem number:24862746

Physical property data

1. Properties: colorless and transparent oily liquid with slightly aromatic odor.

2. Relative density (20℃, 4℃): 1.1905

3. Melting point (℃): 5.5

4. Boiling point (℃): 283.7

5. Flash point (℃): 146

6. Autoignition temperature (℃): 573

7. Refractive index (n20/D): 1.5138

8. Solubility: Slightly soluble in water and mineral oil, miscible with ethanol, ether, chloroform, soluble in benzene, acetone and other organic solvents.

Toxicological data

This product has very little toxicity and does not cause skin damage or allergies except for irritation to the eyes and mucous membranes during use. Rat oral LD50: 69g/kg, the maximum allowable concentration in the air is 5mg/m3.

Ecological data

Slightly harmful to water bodies.

Molecular structure data

1. Molar refractive index: 49.79

2. Molar volume (cm³/mol): 165.2

3. Isotonic specific volume (90.2K ): 416.9

4. Surface tension (dyne/cm): 540.5

5. Polarizability (10^-24cm³): 19.74

Compute chemical data

1. Reference value for hydrophobic parameter calculation (XlogP): None

2. Number of hydrogen bond donors: 0

3. Number of hydrogen bond acceptors: 4

4. Number of rotatable chemical bonds: 4

5. Number of tautomers: none

6. Topological molecule polar surface area 52.6

7. Number of heavy atoms: 14

8. Surface charge: 0

9. Complexity: 200

10. Number of isotope atoms: 0

11. Determine the number of atomic stereocenters: 0

12. Uncertain number of atomic stereocenters: 0

13. Determine the number of chemical bond stereocenters: 0

14. Number of uncertain chemical bond stereocenters: 0

15. Number of covalent bond units: 1

Sex�� and stability

1. Insoluble in water at room temperature, soluble in most organic solvents and hydrocarbons, and has good compatibility with most industrial resins. Dimethyl phthalate is flammable. In case of fire, use water, foam fire extinguishing agent, carbon dioxide, or powder fire extinguishing agent to extinguish the fire.

2. Chemical properties: Stable to air and heat, it will not decompose when heated near the boiling point for 50 hours. When the vapor of dimethyl phthalate passes through a heating furnace at 450°C at a speed of 0.4g/min, only a small amount decomposes, and the products are 4.6% water, 28.2% phthalic anhydride, and 51% neutral substances. The rest is formaldehyde. Under the same conditions, 36% occurred at 608°C, 97% occurred at 805°C, and 100% occurred at 1000°C.

3. When dimethyl phthalate is hydrolyzed in a methanol solution of caustic potassium at 30°C, 22.4% will be hydrolyzed in 1 hour, 35.9% in 4 hours, and 43.8% in 8 hours.

4. Dimethyl phthalate reacts with methylmagnesium bromide in benzene to form 1,2-bis(α-hydroxyisopropyl)benzene at room temperature or when heated on a water bath. . Reacts with phenylmagnesium bromide to form 10,10-diphenylanthrone.

5. Dimethyl phthalate and metal salts such as titanium tetrachloride, tin halide, etc. form crystalline molecular compounds. However, these compounds are easy to absorb moisture and decompose.

6. Found in flue-cured tobacco leaves.

Storage method

1. Store in a cool, dry warehouse, away from fire sources, protected from sun and rain. Severe impacts should be prevented during transportation.

2.A plasticizer with strong solubility. It is used as a plasticizer for nitrile rubber, vinyl resin, cellulose acetate film, cellophane, varnish and molding powder, etc. It can also be used as a solvent for preparing methyl ethyl ketone peroxide. It has excellent film-forming properties, adhesion and waterproof properties, and high thermal stability. However, it is easy to crystallize at low temperatures and is highly volatile. Therefore, it is often used together with plasticizers such as diethyl phthalate for rubber plasticization. When used as an agent, the plasticity of the rubber can be improved, especially suitable for nitrile rubber and chloroprene rubber. It can also be used as anti-mosquito oil and repellent. It has a repellent effect on blood-sucking insects such as mosquitoes, sandflies, Culicoides and gnats. The effective repellent time is 2 to 4 hours.

Synthesis method

1. Sulfuric acid catalytic synthesis: obtained by esterification of phthalic anhydride and excess methanol under normal pressure. Excess methanol is refluxed with water, and 600kg phthalic anhydride, 450g methanol, and 1050mL concentrated sulfuric acid are put into the reaction pot in sequence, heated to reflux for 24 hours, and the esterification temperature is the methanol reflux temperature. After the reaction is completed, methanol is recovered, neutralized with sodium carbonate, washed with water, and then distilled to obtain the finished product. Raw material consumption is: phthalic anhydride 750kg/t, methanol 445kg/t. The esterification reaction formula is as follows:

2. Resin catalytic esterification to synthesize D72 cation exchange resin. Before use, use about 5 times the volume of hydrochloric acid aqueous solution [Yuan (HCl) = 6% ~ 7%] Soak for about 24 hours, then rinse the resin with deionized water until the pH value is the same as the pH value of the deionized water used, and then dry it at 80°C. Place phthalic anhydride and methanol [like (phthalic anhydride):like (methanol) = 1:3], a resin with a mass fraction of 4% in a four-necked flask equipped with a stirrer, thermometer, condenser, and separation funnel, stir, and heat to 110°C, and after 6 hours of reaction, take a sample to measure the acid value. When the requirements are met, stop adding methanol, continue heating for 15 minutes, and filter out the liquid after cooling. Use NaOH (NaOH) = 3% to 4% aqueous solution to neutralize to a pH value of 7 to 8, let it stand for stratification, distill under reduced pressure, and collect the fractions at the corresponding temperature to obtain the product.

3. Tobacco: FC, 40.

Purpose

1. Used as a plasticizer for cellulose acetate, a mosquito repellent and a solvent for polyvinyl fluoride coatings. This product is a plasticizer with strong solubility and is compatible with a variety of cellulose resins, rubber and vinyl resins. Compatible, with good film-forming, adhesive and waterproof properties. Usually combined with diethyl phthalate, it is used in cellulose acetate films, varnishes, transparent papers and molding powders. Used in nitrocellulose, products with high strength, good light resistance and no odor can be obtained. This product can also be used as a plasticizer for nitrile rubber. When mixed with other plasticizers, it can overcome the shortcomings of high volatility and easy crystallization at low temperatures.

2. Mainly used as solvent and plasticizer, with strong plasticizing ability. Compatible with a variety of cellulose resins, rubber, and vinyl resins, it has good film-forming, adhesive and waterproof properties. It is often used together with diethyl phthalate for acetate fiber films, varnishes, cellophane and molding powder. It is also used as a plasticizer for nitrile rubber, and the products have good cold resistance. It can also be used as a solvent for mosquito repellents and polyvinyl fluoride coatings.