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Details of polyhexamethylene adipamide (nylon 66)
2020/7/15 9:17:01   275

Basic information of nylon-66

Chinese name: Polyhexamethylene adipamide

English name: NYLON 6/6

Alias name: Polyhexamethylene adipamide Nylon-66

Item number: 12G5

Molecular formula: C36H66N6O6X2

Molecular weight: 678.95

CAS Number: 32131-17-2

MDL number: MFCD00133999

Properties and stability of nylon-66

In compliance with the use and storage will not decompose.

Nylon-66 has high mechanical strength and good stress crack resistance. It is a nylon material with good abrasion resistance. Nylon-66 has excellent self-lubricating properties, second only to polytetrafluoroethylene and polyoxymethylene, and has good heat resistance. The thermal decomposition temperature is higher than 350°C, and the embrittlement temperature is -30°C. It is a self-extinguishing material with good chemical stability, especially excellent oil resistance, but it is easily soluble in polar solvents such as phenol and formic acid. Strong water absorption, the equilibrium water absorption rate in the atmosphere is 2.5%. Poor dimensional stability but good molding processability. It can be used for injection molding, extrusion, blow molding, spraying, casting molding, and also suitable for molding processes such as machining, welding, and bonding. Adding carbon black can improve the weather resistance of nylon-66.

Physical data of nylon-66

1. Properties: milky white to light yellow translucent or opaque, uniform particles without mechanical impurities and surface moisture.

2. Density (g/mL, 25/4°C): 1.47

3. Melting point (oC): 250-260

4. Refractive index: 1.565

5. Solubility: soluble acetic acid and phenolic compounds

Computational chemistry data of nylon-66  

1. Hydrophobic parameter calculation reference value (XlogP): not available

2. Number of hydrogen bond donors: 4

3. Number of hydrogen bond acceptors: 6

4. Number of rotatable chemical bonds: 10

5. Topological molecular polar surface area (TPSA): 127

6. Number of heavy atoms: 18

7. Surface charge: 0

8. Complexity: 145

9. Number of isotopic atoms: 0

10. Determine the number of atomic stereo centers: 0

11. Uncertain number of atomic stereo centers: 0

12. Determine the number of chemical bond stereo centers: 0

13. Uncertain the number of chemical bond stereo centers: 0

14. Number of covalent bond units: 2

Synthetic method of nylon-66 

1. Synthesis of monomer adipic acid and hexamethylene diamine

Phenol method: phenol is hydrogenated to produce cyclohexanol, and then oxidized with nitric acid to produce adipic acid. Adipic acid is ammoniated and dehydrated to produce adiponitrile, and then hydrogenated to produce hexamethylene diamine.

Cyclohexane oxidation method: Cyclohexane is oxidized by air to generate a mixture of cyclohexanone and cyclohexanol, and then oxidized with nitric acid to generate adipic acid. Use the same method as the phenol method to make hexamethylene diamine.

Butadiene method: Butadiene is chlorinated to generate dichlorobutene, cyanidized to generate dicyanobutene, and then hydrogenated to generate adiponitrile, and adiponitrile is oxidized to generate hexamethylene diamine.

Acrylonitrile electrolysis method: Acrylonitrile electrolytic reduction dimerization to form adiponitrile, and then hydrogenation to form hexamethylene diamine.

Hexanediol method: Cyclohexane is oxidized to generate cyclohexanol and cyclohexanone. After separation, the cyclohexanol is dehydrogenated to cyclohexanone, which is oxidized with acetic acid to generate caprolactone, and then hydrogenated to generate hexanediol, and hexanediol is ammoniated to generate hexamethylene diamine.

2. Polycondensation 

The obtained adipic acid and hexamethylene diamine were neutralized in ethanol at 60° C. to form nylon 66 salt in an equimolar ratio, and then polycondensed at 280° C. under a pressure of 1.76 to 1.96 MPa to obtain nylon 66. It is also possible to directly polymerize equimolar adipic acid and hexamethylene diamine in water to obtain nylon 66 resin.

The use of nylon-66  

1. Nylon-66 is used in the manufacture of machinery, automobile, chemical and electrical equipment parts, wear-resistant, high-strength parts, and packaging film materials

2. Nylon-66 is used to prepare solvent-based nylon adhesives and nylon hot melt adhesives. In industry, nylon 66 is widely used in the production of various mechanical, automotive, chemical, electronic and electrical equipment parts, especially suitable for high-strength or wear-resistant parts, such as various gears, rollers, pulleys, rollers, bearings, Impellers, bellows blades, high-pressure sealing rings, valve seats, gaskets, bushings, various shells, tool handles, support frames, cable cladding, automobile lampshades, etc. in the pump body. Manufacturing parts, elevator guide rails, handrails for building decoration, etc. in electrical equipment such as electronic equipment and relays. It has also been widely used in medical equipment, sports goods and daily necessities, such as baseball batting bats and snowboards. It can also be made into film and aluminum foil to form a laminated film for food packaging, such as flexible packaging cans, beverages, etc.

Overview of the dangers of nylon-66  

Entry route: inhalation, ingestion

Health hazards: It has a certain irritating effect on eyes and skin.

Environmental hazards: harmful to the environment.

Explosion hazard: combustible, the powder can mix with air to form an explosive mixture.

Disposal of nylon-66  

Nature of waste: industrial solid waste

Disposal method: It is recommended to use incineration. The nitrogen oxides discharged from the incinerator are removed by the scrubber.

Disposal precautions: Refer to relevant national and local regulations before disposal.

Precautions for transportation of nylon-66

The packaging should be complete at the time of shipment and the loading should be secure. During transportation, ensure that the container does not leak, collapse, fall, or be damaged. Nylon-66 is strictly prohibited to be mixed with oxidants, edible chemicals, etc. Avoid exposure to sunlight, rain and high temperature during transportation. The vehicle should be thoroughly cleaned after transportation.

Regulatory information of nylon-66  

The following laws, regulations and standards have made corresponding provisions on the safe use, storage, transportation, handling, classification and marking of nylon-66:

The Work Safety Law of the People's Republic of China (adopted at the 28th meeting of the Standing Committee of the Ninth National People's Congress on June 29, 2002);

Occupational Disease Prevention and Control Law of the People's Republic of China (adopted at the 24th meeting of the Standing Committee of the Ninth National People's Congress on October 27, 2001);

Environmental Protection Law of the People's Republic of China (adopted at the 11th meeting of the Standing Committee of the Seventh National People's Congress on December 26, 1989).