Air & Water Reactions
Highly flammable. Soluble in water.
Acrylonitrile is a colourless, flammable liquid. Its vapours may explode when exposed to
an open flame. Acrylonitrile does not occur naturally. It is produced in very large amounts
by several chemical industries in the United States, and its requirement and demand are
increasing in recent years. Acrylonitrile is a heavily produced, unsaturated nitrile. It is
used to make other chemicals such as plastics, synthetic rubber, and acrylic fibres. It has
been used as a pesticide fumigant in the past; however, all pesticide uses have been discontinued.
This compound is a major chemical intermediate used in creating products
such as pharmaceuticals, antioxidants, and dyes, as well as in organic synthesis.
The largest users of acrylonitrile are chemical industries that make acrylic and modacrylic
fibres and high-impact ABS plastics. Acrylonitrile is also used in business machines,
luggage, construction material, and manufacturing of styrene-acrylonitrile (SAN) plastics
for automotive, household goods, and packaging material. Adiponitrile is used to make
nylon, dyes, drugs, and pesticides.
In 1941~1942, the German Degesch Gesellsch company recommended to use acrylonitrile as a food fumigant.
Toxicity: acrylonitrile is of great toxicity to human with comparable toxicity as hydrocyanic acid. Acrylonitrile is highly toxic to insects, and is the most toxic in the main fumigant for controlling various stored grain pests.
Acrylonitrile is used alone or in combination with carbon tetrachloride and has no effect on the germination of many vegetables, grains and flower seeds, but has some damage to maize seeds. The mixture of acrylonitrile and carbon tetrachloride can be used to control the vast majority of stored cereals pests. The results showed that acrylonitrile and carbon tetrachloride, when formulated into mixture in a ratio of 1:1, can be used to control the Phthorimaea operculella Zell occurring in potato under storage without damaging the tubers.
Usage method: Because acrylonitrile and carbon tetrachloride are of high boiling point, upon atmospheric fumigation, in order to be quickly evaporated, it was developed of a simple method which uses cotton cord core to pass through the shallow iron disk bottom. During the beginning of the fumigation, inject a liquid fumigant into the dish and then blow the air through the fan to the cotton core until the evaporation is complete.
Polyacrylonitrile is also known as "acrylic." being a copolymer originated from the copolymerization of acrylonitrile, methyl acrylate and itaconic acid. Its chemical formula is (CH2 = CH-CN) n, being a white powder with the proportion of 1.14 to 1.16. It is almost insoluble in water, fat, weak acid, weak base as well as saliva, gastric liquid. It is soluble in the aqueous solution of dimethyl formamide, dimethyl sulfoxide and inorganic salts (ZnCl2, NaSCN, etc.) and nitric acid. Polyacrylonitrile suitable for making fiber has a molecular weight between 2.05 million and 2.08 million and can be softened and decomposed at 230 °C.
Features: excellent performance, soft, light, warm, and wool close to the "synthetic wool," said. It has high elastic modulus, excellent shape retention, excellent light fastness and radiation resistance, being able to be used in a short time at 180~200 ℃. It has high acid and solvent stability but has poor abrasion resistance and fatigue resistance. It is widely used to replace wool and can be blended with wool, cotton and viscose fiber, making wool fabric, cotton fabric, knitted fabrics, carpets, etc., being especially suitable for outdoor fabric system, and taking advantage of its thermal flexibility to make soft thermal bulk yarn. After the polyacrylonitrile is subject to heat treatment to produce semiconductor fiber, followed by further undergoing high-temperature treatment at 1,000-1,500 °C can lead to high-modulus carbon fiber for producing ablative composite material for artificial satellite or missile shell.
Polyacrylonitrile belongs to low toxicity class. For rats, neither a single oral dose of 2,000~3,000mg/kg nor the inhalation of a concentration of 2,500~3,000 mg /m3 can cause poisoning. It has accumulation property. Polyacrylonitrile fiber is relatively coarse, hard and brittle easy to be broken, similar to glass fiber, being able to produce mechanical stimulation to the skin and mucous membranes, so the spinning worker in contact with polyacrylonitrile fiber can get skin itching and rash. Skin patch test has found no chemical stimulation and sensitization. PRECAUTIONS: Reduce the oligomeric dust through revolutionize the technology; sealing; apply extraction ventilation, and enhance personal protection. Supply iodine and vitamin C-rich foods.
ACRYLONITRILE produces poisonous hydrogen cyanide gas on contact with strong acids or when heated to decomposition. Reacts violently with strong oxidizing agents (dibenzoyl peroxide, di-tert-butylperoxide, bromine) [Sax, 9th ed., p. 61]. Rapidly ignites in air and forms explosive mixtures with air. Polymerizes violently in the presence of strong bases or acids. Underwent a runaway reaction culminating in an explosion on contact with a small amount of bromine or solid silver nitrate [Bretherick, 5th ed., 1995, p. 404].
Acrylonitrile has very active chemical nature with its molecule containing cyano, carbon-carbon double bond, being able to participate in a variety of reactions:
(1) Figure 1 shows the reaction of acrylonitrile.
(2) Figure 2 shows the reaction of acrylonitrile double bond.
(3) Cyanoethylation reaction: it can have reaction with alcohols, phenols, amines, ketones, aldehydes, nitromethane, diethyl malonate, introducing cyanoethyl group into the molecule. The general formula is as follows: R-H + CH2 = CHCN → R-CH2CH2CN.
(4) Polymerization: acrylonitrile is prone to have polymerization, being a monomer of polyacrylonitrile. It can copolymerize with vinyl chloride to generate dinell fiber, and copolymerize with butadiene to produce butadiene-acrylonitrile rubber. Acrylonitrile is the raw materials of polyacrylamide and polypropylene.
1. Cyanide ethanol method: Ethylene oxide is reacted with hydrogen cyanide in the presence of water and trimethylamine to generate cyanoethanol, and then take magnesium carbonate as catalyst in 200-280 °C for dehydration to obtain acrylonitrile with a yield of about 75%. The acrylonitrile produced with this method has high purity. However, the toxicity of hydrocyanic acid is high with the cost being high as well.
2 Acetylene; acetylene is reacted with hydrocyanic acid under 80-90 °C under the catalysis of cuprous chloride-potassium chloride-sodium chloride dilute hydrochloric acid solution to obtain acrylonitrile. This method is simple with good yield which can be up to 97% if calculated on hydrogen Cyanic acid. But there are many side effects with the product being more difficult to refine and the toxicity being also large. Moreover, the price of acetylene raw material is higher than propylene, being lagged behind the ammoxidation of propylene in the technical and economic aspects.
Before 1960, this method is the major way of production of acrylonitrile around the world.
3. Ammonia-ammoxidation method; take propylene, ammonia, air and water as raw materials, add them into the ebullated bed or fixed-bed reactor according to a certain ratio; under the action of the phosphorus molybdenum bismuth or antimony iron-based catalyst using silica gel as the carrier and 400-500 ℃ as well as normal pressure, they will react to form acrylonitrile.
And then through the neutralization tower, use dilute sulfuric acid to remove unreacted ammonia, and then absorb acrylonitrile gas using water by the absorption tower to form aqueous solution. The aqueous solution is sent through the extraction tower to separate out the acetonitrile. Remove the hydrogen cyanide in the dehydrocyanic acid tower, further go through dehydration and rectification to derive acrylonitrile products with the one-way yield of up to 75%. The by-products include acetonitrile, hydrocyanic acid and ammonium sulfate. This method is of the most industrial production value at present.
Its preparation method mainly uses the propylene ammoxidation method; take the propylene, the ammonia and the oxygen in the air as the raw material; carry out the reaction in the presence of catalyst; the catalyst mainly consists of the phosphorus, molybdenum, bismuth compound with the mole ratio of propylene, ammonia and air being (1 to 1.2): (1.8 to 2.3); the reaction temperature is 400 to 500 ℃, the reaction pressure is normal pressure, and the reactor is a fluidized bed. The reaction equation:
CH2 = CH2-CH3 + NH3 + 3/2O2 → CH2 = CH-CN + 3H2O
The reaction yield of acrylonitrile is 60% to 75%.
1. It can be used for the synthesis of polyacrylonitrile, nylon 66, acrylonitrile-butadiene rubber, ABS resin, polyacrylamide, acrylic esters, also used as a grain smoked agent
2. Acrylonitrile is the intermediate of fungicide bromothalonil, Propamocarb, Pesticide Chlorpyrifos and the intermediate of insecticidal bisultap, cartap. It can also be prepared for the production of methyl chrysanthemum pyrethroid, being also the intermediate of the insecticides chlorfenapyr.
3. Acrylonitrile is an important monomer for synthetic fibers, synthetic rubbers and synthetic resins. Acrylonitrile is made from acrylic fiber (acrylic) with its performance being quite similar to wool, also called (synthetic wool). The copolymerization of acrylonitrile and butadiene can lead to nitrile rubber, having excellent oil resistance, cold resistance, wear resistance, and electrical insulation properties, and being stable under the action of most chemical solvents, sunlight and heat. Copolymerization of acrylonitrile and butadiene, styrene can lead to ABS resin with light property, cold-resistant, good impact resistance and so on. Acrylonitrile hydrolysis can lead to acrylamide and acrylic acid and its esters. They are important organic chemical raw materials, acrylonitrile can also be made of adiponitrile through electrolytic hydrogenation coupling system; from adiponitrile hydrogenation, and we can also obtain hexamethylenediamine which is the raw materials of nylon 6. It can be used to make water repellent and adhesive, also used in other organic synthesis and pharmaceutical industry, and as a cereal fumigant. In addition, the product is also a non-proton polar solvent.
4. t can be used as a standard substance for chromatographic analysis. It is also used for the manufacture of rubber, plastics, organic synthesis and pesticides.
5. For calibration of instruments and devices; evaluation methods; work standards; quality assurance/quality control;
Unsaturated nitrile compounds
Acrylonitrile is also known as cyanoethylene, 2-acrylonitrile, vinyl nitrile, grain fumigants, Ventox, Acritet, being a kind of unsaturated nitrile compound. It was first synthesized by C. Moureu in 1893. Its molecular formula is C3H3N and structural formula is CH2 = CHCN. It appears as colorless flammable liquid, being volatile, explosive and flammable. It has slightly special smell with sweetness. The relative molecular mass is 53.06. The relative density is 0.8060. Melting point:-83.55 °C; Boiling point: 77.3 to 77.4°C, 64.7°C (66.661 103 Pa), 45.5°C (33.331 103 Pa), 3.6°C (13.331 103 Pa), 8.7°C (6.666 103 Pa). Flash point:-5 °C. Flash point: 0 °C. Refractive index: 1.3911. Viscosity: 0.34mPa • s (25 ℃). Soluble in water: 0 °C 7.2, 10 °C: 7.25, 20 °C: 7.35, 30 °C: 7.60, 40 °C: 7.80, 50 °C: 8.3, 60 °C: 9.0, 70 °C: 9.8, 80 °C: 10.8; It is soluble in acetone, ethanol, benzene, carbon tetrachloride, ethyl acetate, methanol, ethyl ether and so on.
It can form azeotropic mixture with water with the content of 88%, azeotropic point of 71 ℃; it can form azeotropic mixture with benzene with the content of 47%, azeotropic point of 73.3 ℃; it can form azeotropic mixture with carbon tetrachloride with the content of 21 %, azeotropic point of 66.2 ℃;
It can form azeotropic mixture with methanol with the content of 39%, azeotropic point 61.4 ℃. Its vapor and air can form an explosive mixture, with the explosive limit at 25 ℃ being 3.05%~17.0% (volume fraction). The molecular structure of Acrylonitrile contains double bonds and cyano bonds, being chemically active. Its double bonds can undergo self-polymerization and copolymerization with other compounds, diene addition, reduction, halogenation and reaction with nucleophilic agents; the cyano group can undergo hydration, hydrolysis, alcoholysis and condensation. This product is easy to form a white powder upon polymerization. This product has toxic vapor with a large number of inhalation being able to cause nausea, headache and other symptoms. It can also cause poisoning upon invading the skin. After poisoning, the use of drugs for hydrocyanic acid detoxification such as amyl nitrite and sodium thiosulfate is often ineffective; indicating that it is not only the decomposition of hydrocyanic acid that is toxic, but also acrylonitrile itself is toxic! Mice intravenous LD50:15mg/kg, Rat oral LD50: 93mg/kg. The maximum allowable concentration of the workplace is 20 × 10-6. The antidote for this product includes sodium thiosulfate, L-cysteine and methionine.
The above information is edited by Tongtong from Chemicalbook.
Acrylonitrile is a raw material used extensively in industry,
mainly for acrylic and modacrylic fibers, acrylonitrile-butadiene-styrene
and styrene-acrylonitrile resins,
adiponitrile used in nylon’s synthesis, for nitrile rubber,
and plastics. It is also used as an insecticide. This very
toxic and irritant substance is also a sensitizer and caused
both irritant and allergic contact dermatitis in a production
It appears as colorless volatile liquid with sweet taste and being slightly foul. It is soluble in acetone, benzene, carbon tetrachloride, ether, ethanol and other organic solvents. Slightly soluble in water
ChEBI: A nitrile that is hydrogen cyanide in which the hydrogen has been replaced by an ethenyl group.
On the eve of World War II, it was discovered that acrylonitrile copolymer can improve the oil resistance and solvent resistance of synthetic rubber and people began to be taken it seriously. During the war, it was developed in Germany of the manufacturing process through epoxidation of ethylene, followed by addition with hydrogen cyanide to produce cyanide ethanol, and finally dehydration. It was later developed of addition of hydrogen cyanide to acetylene under the catalysis of cuprous chloride. After 1960, it had been developed of new production process in the Ohio standard oil company, using propylene as raw material for ammoxidation reaction to obtain it. This process has led to great changes in industrial production. Owing to the availability of raw materials and the reduction in the cost, there is a sudden surge in production of acrylonitrile. In 1983, the world's annual output reached 3 million tons, of which the production amount of Ohio standard oil can account for 90%.
Acrylonitrile is easy to undergo polymerization, being able to produce polyacrylonitrile fiber (under the trade name of acrylic or bulk). Its short fiber is similar to wool, also known as artificial wool. It feels soft by hand with excellent elasticity. It can co-polymerize with vinyl acetate to generate synthetic fibers (under the commercial name of Austrian Lun). In 1950, it was first put into industrial production by the United States DuPont. The majority of acrylonitrile is used for synthetic fiber with the amount accounting for about 40~60% of the total. With copolymerization with butadiene copolymerization, it can generate oil-resistant nitrile rubber. Acrylonitrile dimerization and hydrogenation can be lead to adiponitrile, with then hydrogenation being able to obtain hexamethylene diamine, which is one of the raw materials of polyamide (nylon 66). The co-polymer of acrylonitrile and butadiene, styrene terpolymer is a high-quality engineering plastics, referred to as ABS resin.
Materials are too dangerous to health to expose fire fighters. A few whiffs of vapor could cause death or vapor or liquid could be fatal on penetrating the fire fighter's normal full protective clothing. The normal full protective clothing and breathing apparatus available to the average fire department will not provide adequate protection against inhalation or skin contact with these materials. Explosion hazard is moderate. Acrylonitrile is flammable and explosive at normal room temperatures. Can react violently with strong acids, amines, strong alkalis. Vapors may travel considerable distance to source of ignition and flash back. Dilute solutions are also hazardous (flash point of a solution of 2 percent in water is 70F). When heated or burned, toxic hydrogen cyanide gas and oxides of nitrogen are formed. Avoid strong acids, amines, alkalis. Incompatible with strong oxidizers (especially bromine) copper and copper alloys. Unstable, moderate hazard is possible when Acrylonitrile is exposed to flames, strong acids, amines and alkalis. May polymerize spontaneously in the container, particularly in absence of oxygen or on exposure to visible light. If polymerization occurs in containers, there is a possibility of violent rupture.
Acrylonitrile is classified as very toxic. Probable oral lethal dose for human is 50-500 mg/kg (between 1 teaspoon and 1 oz.) for a 70 kg (150 lb.) person. Irritant skin dose -- 500 mg. Toxic concentrations have been reported at 16 ppm/20 min. Acute toxicity is similar to that due to cyanide poisoning, and the level of cyanide ion in blood is related to the level of poisoning. Inhalation or ingestion results in collapse and death due to tissue anoxia (lack of oxygen) and cardiac arrest (heart failure).
Wash acrylonitrile with dilute H2SO4 or dilute H3PO4, then with dilute Na2CO3 and water. Dry it with Na2SO4, CaCl2 or (better) by shaking with molecular sieves. Fractionally distil it under N2. It can be stabilised by adding 10ppm tert-butyl catechol. Immediately before use, the stabilizer can be removed by passage through a column of activated alumina (or by washing with 1% NaOH solution if traces of water are permissible in the final material), followed by distillation. Alternatively, shake it with 10% (w/v) NaOH to extract inhibitor, and then wash it in turn with 10% H2SO4, 20% Na2CO3 and distilled water. Dry for 24hours over CaCl2 and fractionally distil under N2 taking fraction boiling at 75.0-75.5oC (at 734mm). Store it with 10ppm tert-butyl catechol. Acrylonitrile is distilled off when required. [Burton et al. J Chem Soc, Faraday Trans 1 75 1050 1979, Beilstein 2 IV 1473.]
Manufacture of acrylic fibers. In the plastics, surface coatings, and adhesives industries. As a chemical intermediate in the synthesis of antioxidants, pharmaceuticals, dyes, surface-active agents, etc. In organic synthesis to introduce a cyanoethyl group. As a modifier for natural polymers. As a pesticide fumigant for stored grain. Experimentally to induce adrenal hemorrhagic necrosis in rats.
The main purpose and role of acrylonitrile
(1) acrylonitrile can be used for the manufacture of acrylonitrile fiber and carbon fiber; used in the production of sodium L-glutamate (i.e. MSG), acrylate (raw materials of organic synthesis and paint), methine glutaronitrile (ABS modifier, the raw material of 2-methyl-1,5-diamine), α, α-dichloropropionic acid and α, α, β-trichloropropionic acid (used as the raw materials of herbicide), succinonitrile (the raw materials of succinate and 1,2-Butanediol), pimelic acid (for the production of plasticizers, plant growth regulators and pharmaceutical raw materials) and other derivatives.
(2) Important raw materials of organic synthesis for the production of dyes, antioxidants, surfactants and so on.
(3) monomers for synthesis, mainly used in the manufacture of synthetic fibers (acrylic); copolymerization with butadiene can produce oil, cold-resistant nitrile rubber; copolymerization with butadiene and styrene can produce three-way engineering plastics (ABS resin); control of acrylonitrile hydrolysis conditions, under the action of copper as the catalyst, we can obtain acrylamide; after polymerization of acrylamide, we can obtain polyacrylamide, which is an important industrial raw materials.
(4) Acrylonitrile can undergo full hydrolysis under the action sulfuric acid, being able to lead to acrylic acid; electrolytic hydrogenation can obtain adiponitrile, and used for further preparation of hexamethylene diamine (nylon 66 raw materials); for pesticides (livestock anthelmintic) Pharmaceutical raw materials; for grain fumigants.
(5) Acrylonitrile is an excellent aprotic polar solvent.