1,1-Dichloroethylene 1,1-Dichloroethylene
Structural formula
| Business number | 01JK |
|---|---|
| Molecular formula | C2H2Cl2 |
| Molecular weight | 97 |
| label |
vinylidene chloride, Vinylidene chloride |
Numbering system
CAS number:75-35-4
MDL number:MFCD00011653
EINECS number:200-864-0
RTECS number:YZ8061000
BRN number:1733365
PubChem number:24872048
Physical property data
1. Properties: colorless liquid with unpleasant odor. [1]
2. Melting point (℃): -122.6[2]
3. Boiling point (℃): 31.7[3]
4. Relative density (water = 1): 1.21[4]
5. Relative vapor Density (air=1): 3.3[5]
6. Saturated vapor pressure (kPa): 66.5 (20℃)[6]
7. Heat of combustion (kJ/mol): -1095.9[7]
8. Critical temperature (℃): 220.8[8]
9. Critical pressure (MPa): 5.21[9]
10. Octanol/water partition coefficient: 2.13 [10]
11. Flash point (℃): -19 (CC); -15 (OC) [11]
12. Ignition temperature (℃): 570[12]
13. Explosion upper limit (%): 16[13]
14. Lower explosion limit (%): 5.6[14]
15. Solubility: insoluble in water. [15]
16. Viscosity (mPa·s, 20ºC): 0.3302
17. Flash point (ºC): 570
18. Heat of evaporation (KJ/mol, b.p.): 26.197
19. Heat of fusion (KJ/mol): 6.519
20. Heat of formation (KJ/mol, 25ºC, Liquid): 25.1
21. Specific heat capacity (KJ/(kg·K), 25.15ºC, constant pressure): 1.155
22. Heat of polymerization (KJ/mol): 60.7
23. Relative density (25℃, 4℃): 1.4249
24. Solubility parameter (J·cm-3)0.5: 16.813
25. van der Waals area (cm2·mol-1): 6.110×109 sup>
26. van der Waals volume (cm3·mol-1): 41.430
27. Liquid phase Standard claimed heat (enthalpy) (kJ·mol-1): -23.9
28. Liquid phase standard hot melt (J·mol-1 ·K-1): 112.4
29. Gas phase standard claims heat (enthalpy) (kJ·mol-1): 2.4
30. Gas phase standard entropy (J·mol-1·K-1): 287.98
31. Gas phase standard free energy of formation ( kJ·mol-1): 25.4
32. Gas phase standard hot melt (J·mol-1·K-1)：66.93
Toxicological data
1. Acute toxicity[12]
LD50: 200mg/kg (rat oral)
LC50: 6350ppm (rat inhalation, 4h)
2. Irritation No data available
3. Asia Acute and chronic toxicity[13]
Animal exposure 0.379g/m3 and 0.199g/ m3, 8 hours a day, 5 days a week, liver and kidney damage will occur after a few months. Exposure below 0.099g/m3 will cause mild liver and kidney disease.
4. Mutagenic[14]
Microbial mutagenicity: Salmonella typhimurium 5%�This method can be divided into two types. One is that all reactions are carried out in a continuous reactor, the batching ratio (NaOH:CH2ClCHCl2) is (1-1.2:1), and the content of sodium hydroxide is 10%-20%. The reaction temperature is 50-70°C, the product content is 94%, and the yield is 93.9%. The second method is to use sodium chloride-containing sodium hydroxide and 1,1,2-trichloroethane to convert into vinylidene chloride. This method directly uses electrolyte, and the sodium chloride generated after dehydrochlorination can be returned to the electrolysis system for recycling. Therefore, it is most suitable for the production of vinylidene chloride in chlor-alkali plants.
②Calcium hydroxide method: This method can be divided into four types. First, the raw material calcium hydride concentration is 200g/L, the calcium carbonate concentration is <20g/L, the calcium hydroxide excess is 50%, and the system temperature is 80°C at the beginning of the reaction, and then rises to 90-92°C. The crude vinylidene chloride obtained after the reaction is purified by distillation, and the yield can reach more than 80%. Secondly, since the control step of the reaction to generate vinylidene chloride is material transfer at the interface, a small amount of surfactant and water should be added to improve the contact effect. Third, in order to simplify the process, the reaction and distillation are combined in one tower. Fourth, first carry out the addition reaction of vinyl chloride and chlorine through the reactor, and then add 10% calcium hydroxide to convert 1,1,2-trichloroethane into vinylidene chloride. After refining, the product vinylidene chloride is obtained. Ethylene dichloride.
③Ammonium hydroxide method: Xudao Company proposed to use ammonium hydroxide to replace sodium hydroxide and calcium hydroxide. The feed ratio is NH4OH:CH2ClCHCl2=2:1 (mol), the reaction temperature is 120℃, and the pressure is about 0.86MPa, conversion rate 52.1%, ammonium chloride, ammonia and unreacted 1,1,2-trichloroethane can be recycled. The chlorination reaction is carried out in a tower reactor. The tower is filled with trichloroethane. Iron rings are stacked in the tower as a catalyst. Chlorine and vinyl chloride are introduced from the bottom of the tower in a ratio of 1.05:1 (mol). The reaction temperature is controlled at 35-45℃. Since the reaction liquid of vinyl chloride and chlorine gas can circulate naturally depending on the temperature difference, it can also be forced to circulate using a pump. The reaction temperature is about 75°C and the pressure is normal pressure. The generated vinylidene chloride passes through the rough separation tower on the kettle and then through the rectification tower to purify and refine the product vinylidene chloride. At present, all domestic factories use kettle-type alkaline hydrolysis reactors, most of which operate intermittently. In the past, some people used 2.5%-3.0% milk of lime as alkali solution, but later switched to dilute sodium hydrochloride solution due to clogging of equipment. In the intermittent operation, the reaction temperature was raised to 85°C in the later stage of alkaline hydrolysis. As a result, the impurities in the crude vinylidene chloride increased significantly, which made refining difficult.
2. Alkaline chlorination method of ethyl chloride: This method uses 1,2-dichloroethane as raw material, and chlorides it into 1,1, 2-Trichloroethane, in addition to 1,2-dichloroethane and chlorine, 12% ethylene is also added to the reactants to accelerate the chlorination reaction of dichloroethane. Trichloroethane is purified through a low-boiling tower and a high-boiling tower and then reacts with a dilute alkali to remove a molecule of hydrogen chloride to obtain vinylidene chloride; crude vinylidene chloride is refined through a low-boiling tower and a high-boiling tower to obtain pure vinylidene chloride. Ethylene Products. The chlorination yield of the above process is 95.4%, the alkaline hydrolysis yield is 99.8%, and the product purity is as high as 99.9%.
3. Methyl chloroform thermal cracking hydrogen chloride method: This method uses vinyl chloride as raw material, and is added with hydrogen chloride to generate 1,1-dichloroethane; dichloroethane is chlorinated at a high temperature of 480°C , the chlorinated liquid products obtained mainly include vinylidene chloride, methyl chloroform (1,1,1-trichloroethane) and vinyl chloride. By-products include trichlorethylene, cis-dichloroethylene, trans-dichloroethylene, polychlorethane and hydrogen chloride. The chlorinated liquid is distilled to separate the above products, vinyl chloride and hydrogen chloride are returned to the addition process, trichlorethylene is sold as a commodity, methyl chloroform is cracked into vinylidene chloride by high temperature, the cracked mixture and the chlorinated liquid are combined and separated by distillation. Polymerization inhibitor is added to vinylidene chloride for sale as a commodity. 1,1-dichloroethane and 1,2-dichloroethylene are chlorinated in liquid phase at low temperature to form 1,1-dichloroethane and tetrachloroethane, and then sent to Enter the high temperature chlorinator.
4. Ethane chlorination and thermal cracking to remove hydrogen chloride: This method uses ethane as raw material, which is chlorinated at a high temperature of 426.6°C into hydrogen chloride, vinyl chloride, vinylidene chloride, ethyl chloride, A mixture of 1,1-dichloroethane and methyl chloroform is used to separate the above product by fractional distillation. Hydrogen chloride is used in the vinyl chloride hydrochlorination reactor; methyl chloroform is cracked at high temperature to decompose a molecule of hydrogen chloride to generate vinylidene chloride, which is combined with the chlorinated liquid for separation and purification to obtain the high-purity product vinylidene chloride.
5. High-temperature thermal dehydrochlorination method: First, preheat 1,1,2-trichloroethane to 250°C, and then pass it into a tubular reactor for decomposition reaction. The reaction temperature is 350-500°C. The advantage of this method is that the decomposition product hydrogen chloride can be utilized, but the by-product 1,2-dichloroethylene is more.
Purpose
1. This product is a copolymer based on (containing at least 80%), which can produce polyvinylidene with fire resistance. Various synthetic resins can be produced by copolymerizing 1,1-dichloroethylene with acrylonitrile, butadiene, acrylate, styrene, etc. Vinylidene chloride resin can be processed into fibers or films and used for surface coatings on paper or plastic films. Polyvinylidene chloride fiber can be used to produce fabrics, tents, insect nets, car seat cushions, etc. Polyvinylidene chloride film has lower air permeability and moisture permeability than other plastic films, and is suitable for food packaging. Copolymers with methacrylic acid, methyl methacrylate, etc. can be used in the film industry. Mainly used as raw material for the manufacture of vinylidene chloride resin and 1,1,1-trichloroethane. Because of its high volatility, it is usually not used as a solvent.
2. Used in manufacturing various copolymers, synthetic fibers, adhesives and in organic synthesis. [26]
synthesis. [26]
