ChEBI: A member of the class of acrylamides that results from the formal condensation of acrylic acid with ammonia.
1. Acrylonitrile sulfate hydration; Acrylonitrile and water is hydrolyzed into acrylamide sulfate in the presence of sulfuric acid and then treated neutralized liquid ammonia to give ammonium sulfate and acrylamide: The reaction products further undergoes filtering and separation. Crystallize the filtrate, dry to obtain the final product. The disadvantage of this method is by-producing a large number of low-value, low fertilizing efficacy-ammonium sulfate and causing serious sulfuric acid corrosion and pollution. This method can produce by-products of 2280 kg ammonium sulfate in per tons of acrylonitrile.Material consumption amount: Acrylonitrile (100%) 980kg/t, sulfuric acid (100%) 200kg/t, ammonia (100%) 700kg/t.
2. Direct hydration of acrylonitrile: acrylonitrile is directly hydrated by water with copper being the catalyst at 85-125 °C and 0.3-0.4MPa pressure. The yielding aqueous solution of acrylamide (containing only small amounts of by-products) can be directly sold as a finished product. This method avoids acrylamide dust pollution and is advantageous for labor protection for using aqueous solution. Reference Product Specifications: appearance: white flakes or powder. With first-grade product containing content ≥95%; Secondary-grade content ≥90%; grade III content ≥85%.
3. Enzyme catalysis; at room temperature transfer the acrylonitrile solution into the fixed-bed reactor containing bacteria catalyst; after the reaction, 100% of acrylonitrile is converted into acrylamide. After isolation and even without the necessity of refining and concentration, we can get the acrylamide industrial products.
4. Concentrated sulfuric acid hydration method: mixture containing sulfate, phenothiazine (polymerization inhibitor), and water is added to the reactor; stir slowly with dropping acrylonitrile After the addition is completed, raise the temperature to 95~100 °C, keep the temperature for 50 min. Cool to 20~25 °C, dilute with an appropriate amount of water, neutralize with sodium carbonate, filtrate to obtain aqueous acrylic acid solution. Further cool and crystallize, separate, dry to obtain the completed products.
5. Catalytic hydration method; acrylonitrile and water undergoes liquid phase hydration in the presence of copper-based catalyst; It is generally used for continuous production with the reaction temperature being 85~120 °C, reaction pressure being 0.29~0.39 MPa, feed concentration of 6.5%, airspeed being 5 L/ h, the conversion rate being 85%, and selectivity being about 95% and the concentration of acrylamide in the reaction being 7% to 8%. Aqueous solution obtained by this method may be directly used as the product for sale.
1. It can be used as a monomer of polyacrylamide. Its polymer or copolymer is used as chemical grouting materials, soil conditioners, flocculants, adhesives and coatings.
2. Polyacrylamide, when used as a kind of additive, can improve the oil recycling efficiency. When used as flocculants, it can be used for sewage treatment. It can also be used as a paper strength agent.
3. Acrylamide is the most important products in acrylamide and methacrylamide-based products. Since its application in industry in 1954, the demand gradually increase. It is mainly used for the preparation of water soluble polymers which can be used as additives to improve oil recovery; as a flocculant, thickening agents, and paper additives. A small amount of acrylamide is introduce the hydrophilic center into the lipophilic polymer to improve the viscosity, increase the softening point and improve anti-solvents ability of resin, and can aso introduce a center for the coloring property of dye. Acrylamide is also often used as a component of the photopolymer. For the vinyl polymer, its crosslinking reaction can take advantage of this kind of reactive amide groups. Acrylamide can co-polymerizze with certain monomers such as vinyl acetate, styrene, vinyl chloride, vinylidene chloride, and acrylonitrile to obtain a polymer with a variety of applications.
The main application areas: (1) used for the oilfield; the materials can be used in oilfield injection of wells for adjustment of the injection profile. Mix this product with initiator, and deaerator and inject into the high permeability layer part of water wells. This will lead the formation of high-viscosity polymer unearth of the stratum. This can plug the large pore, increase the swept volume of oil, and enhance the oil recovery. In addition, the product polymer or copolymer can be used for tertiary oil recovery, fracturing, water shutoff, drilling mixing process and chemical grouting. (2) It can be used as flocculants. Its partially hydrolyzed product and its graft copolymer of methyl cellulose can be used in wastewater treatment and sewage treatment. (3) Soil conditioner; using the hydrolyzed product as soil amendments can aggregate soil and can improve air circulation, water permeability and water retention. (4) Modification of fiber and resin processing; using acrylamide for carbamylation or graft polymerization can improve the resin arrangement of a variety of fiber containing synthetic fiber, as well as for warp and printing paste in order to improve the basic physical properties of fabrics as well as preventing wrinkle, shrink and keeping a good hand feeling. (5) It can be used as paper enhancer; copolymer of acrylamide and acrylic acid or partial hydrolysis products of polyacrylamide can be used as paper strength reinforcing agent for either replacing or combining with starch, and water-soluble amino resin. (6) it can be used as an adhesive agent including glass fiber adhesive agent with the combination of phenolic resin and polyacrylamide solution, as well as pressure sensitive adhesive combined with synthetic rubber.
4. It is the raw material for producing polyacrylamide and related products.
5. It can be used as the monomer of polyacrylamide. Its polymer or copolymer can be used as chemical grouting materials, soil conditioners, flocculants, adhesives and coatings. Polyacrylamide, as an additive, can improve oil recovery. As a kind of flocculants, it can be used for waste water treatment as well as paper strength enhancer can. It is the raw material for producing polyacrylamide and related products. It can also used for determining the relative molecular weight of acid.
Used as chemical intermediate in production of polyacrylamides, for use in protein electrophoresis (PAGE), synthesis of dyes and copolymers for contact lenses. It is reasonably anticipated to be a hum
ACRYLAMIDE SOLUTION reacts with azo and diazo compounds to generate toxic gases. Flammable gases are formed with strong reducing agents. Combustion generates mixed oxides of nitrogen (NOx). Spontaneous, violent polymerization occurs at the melting point (86°C of the undissolved solid [Bretherick, 5th ed., 1995, p. 428].
Crystallise acrylamide from acetone, chloroform, ethyl acetate, methanol or *benzene/chloroform mixture, then vacuum dry and store it in the dark under vacuum. Recrystallise it from CHCl3 by dissolving 200g in 1L, heating to boiling and filtering without suction in a warmed funnel through Whatman 541 filter paper; allowing to cool to room temperature and keeping at -15o overnight. The crystals are collected with suction in a cooled funnel and washed with 300mL of cold MeOH. The crystals are air-dried in a warm oven. [Dawson et al. Data for Biochemical Research, Oxford Press 1986 p. 449, Beilstein 2 IV 1471.] CAUTION: Acrylamide is extremely TOXIC (neurotoxic), and precautions must be taken to avoid skin contact or inhalation. Use gloves and handle in a well-ventilated fume cupboard.
Acrylamide is a white crystalline chemical substance and is a raw material for production of polyacrylamide. Solid acrylamide (abbreviated AM) is usually colorless and transparent flaky crystals with pure product being white crystalline solid which is soluble in water, methanol, ethanol, propanol, and slightly soluble in ethyl acetate, chloroform, and benzene. It can be hydrolyzed to acrylic acid in acidic or alkaline environment.
Acrylamide is a large class of the parent compound of monomers including methacrylamide, the AMPS (anionic monomer, 2-Acraylamide-2-Methyl Propane Sulfonic Acid), the DMC (cationic monomer, methyl-acryloyloxyethyl trimethyl ammonium chloride) and N-substituted acrylamide compound.
Occupational exposure is mainly seen in acrylamide production and the synthesis of resins, adhesives, etc. It is also possible for contract in underground construction, upon soil improvement, painting, paper industry and garment processing.
At daily life, people can touch it in smoking, drinking and eating the starchy foods processed at high temperature.
The above information is edited by the chemicalbook of Dai xiongfeng.
Inhalation or contact with material may irritate or burn skin and eyes. Fire may produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution.
It is odorless and colorless crystal. It is soluble in water, ethanol, acetone, ether, and methyl chloroform, and slightly soluble in toluene but insoluble in benzene.
Air & Water Reactions
Acrylamide is very soluble in water. The solvent is not necessarily water soluble.
For polymerization of acrylamide, people generally applies chemical catalytic systems or photocatalytic systems.
(1) Chemical catalyst system: chemical catalytic polymerization of acrylamide is done in the systems containing the trigger and accelerator. Trigger reagents participating the reaction include ammonium persulfate (or potassium persulfate) and hydrogen peroxide while the accelerator includes dimethylamine propionitrile and so on. Because the polymerization of acrylamide can performed under both acidic or alkaline conditions, so the choice of trigger and accelerator should be changed with pH.
When the aqueous solution of acrylamide (Arc), cross-linking agent (Bis) and tetramethylethylenediamine (tetramethyl ethylene diamine, TEMED) is added into ammonium persulfate (ammoniumpersulfate, AP), AP [(NH4) 2S20s] immediately generate radical (S: OU-2S07), after the reaction between Arc and the free radicals, then it becomes "activate", activated Arc connects with each other to form a long chain poly. The solution containing this polymer chain, although is sticky but can’t form a gel and can form into a gel only when Bis is also presented. In the AP-TEMED catalyzed system, the initiating polymerization rate between Arc and Bis is positively proportional to the square root of the concentration of AP and can occur rapidly under alkaline conditions. For example, the complete polymerization of 7% Arc, only needs 0.5 h upon pH8.8; however, needs 1.5 h upon pH4.3. In addition, temperature, oxygen molecules and other impurities will also affect the rate of polymerization. Usually faster polymerization occurs at room temperature than at 0 °C; Solution subjecting to pre-pumping also has faster polymerization rate than that without pre-puming.
(2) Photocatalytic System: This catalysis of this system is vitamin B2. Photo-polymerization process is catalyzed at light excitation. Vitamin B: in the presence of oxygen and ultraviolet light, can produce products containing free radicals whose function is similar as AP agent described above. The mixture is usually placed next to a fluorescent lamp where the reaction can take place. When using Vitamin B2 for catalyzing, TEMED is not demaned, but adding it can accelerate the rate of polymerization. Gel formed by photo-polymerization is milky white like with poor transparency. The advantage of using this catalyst is that it needs a very small amount (1ml/100mi) without any adverse effect on the analysis of samples; polymerization time can be extended or shortened by chaning the light intensity and time.
The apertube of chemical polymerization is smaller thant that of photo-polymerization. The reproducibility and transparency is also better for the former one than the latter one. However, the trigger of the chemical polymerization, AP, is a strong oxidizing agent, tend to cause loss of activity of certain protein molecules if remaining in the gel or cause distortion on the electrophoresis pattern.
At the end of 19th century, people had first made acrylamide using propylene chloride and ammonia.
In 1954, American Cyanamid Company uses sulfuric acid hydrolysis of acrylonitrile for industrial production.
In 1972, Mitsui Toatsu Chemicals, Inc. had first established the skeleton copper (see the metal catalyst) catalyzed acrylamide synthesis via acrylonitrile hydration. Then other countries have developed different types of catalyst and applied this technology for industrial production.
In 1980s, Japanese Nitto Chemical Industry Company has achieved that using biological catalyst for industrial production of acrylamide from acrylonitrile.
Sulfuric acid hydration way
Acrylonitrile and water is hydrolyzed into acrylamide sulfate in the presence of sulfuric acid and then treated neutralized liquid ammonia to give ammonium sulfate and acrylamide:
CH2 = CHCN + H2O + H2SO4 → CH2 = CHCONH2 ? H2SO4 CH2 = CHCONH2 ? H2SO4 + 2NH3→ CH2 = CHCONH2 + (NH4) 2SO4
The disadvantage of this method is by-producing a large number of low-value, low fertilizing efficacy-ammonium sulfate and causing serious sulfuric acid corrosion and pollution.
Catalytic hydration way
Acrylonitrile is reacted with water by the copper-based catalyst to have liquid phase hydration reaction at 70~120 °C at 0.4MPa pressure.
CH2 = CH-CN + H2O → CH2 = CHCONH2; Filter the catalyst after reaction catalyst; recycle the unreacted acrylonitrile; acrylamide solution was concentrated and cooled to give crystals. This is a simple method with the yield up to 98%.
A solution of a colorless crystalline solid. Flash point depends on the solvent but below 141°F. Less dense than water. Vapors heavier than air. Toxic oxides of nitrogen produced during combustion. Used for sewage and waste treatment, to make dyes and adhesives.
Acrylamide is moderately toxic and have a stimulating effect on eyes and skin. It can be absorbed through the skin, respiratory and digestive tract, and have in vivo accumulation effect which mainly affects the nervous system with acute poisoning being very rare.
Frequently close contact can cause sub-acute onset such as drowsiness and cerebellar dysfunction, manifested as eye level tremors, slurred speech, and unstable finger-nose, knee-shin test, rotation movement disorders, unsteady gait and so on. Sensorimotor polyneuropathy disease may occur after 2 weeks manifested as numbness, prickly, weakness in lower limb. Tuning fork vibration sense and achilles tendon reflexes have a value of early diagnosis. EMG examination revealed: distal sensory potentials significantly decreased with neurogenic damage; it may be associated with much spontaneous denervation potentials.
Long-term low-level exposure can cause chronic poisoning manifested as headache, dizziness fatigue, drowsiness, prickly fingers, and numbness, often accompanied by palm redness, scaling, palms and foot sweating, and with further development into limb weakness, muscle paining, and cerebellar dysfunction, staggering gait, and being prone to forward dumping. Neurological examination can identify the reduction or loss of deep reflex, reduction of tuning fork vibration sense and position sense, and positive symptoms in Romberg test and so on. EMG examination showed similar behavior as sub-acute toxicity while EEG abnormalities can be mild.
The most interesting issue about chronic toxicity of acrylamide is its carcinogenicity. Study have confirmed that acrylamide can be absorbed into the body through a variety of ways, including through the digestive tract giving the fastest absorption rate; it is widely distributed in body tissues including breast milk, so there may exist the possibility of transmission between mother and child. After it enters into the body, it is converted into glycidamide through the action of cytochrome oxidase. Glycidamide is more easily to bind with the guanine on DNA to form adducts, causing the genetic damage and mutations.
Animal studies have found that acrylamide can cause multiple organ tumors in rats or mice, such as breast, thyroid, testes, adrenal glands, central nervous system, oral cavity, uterus, and pituitary tumors. But there is no sufficient epidemiological evidence that the dietary intake of the product has significant correlation with some human tumors. International Cancer Research (IARC) has evaluated the carcinogenicity of acrylamide, it was listed as a category 2 carcinogen (2A), meaning that it may be carcinogenic to human beings. The main basis is that it can be converted to carcinogenic active metabolite epoxypropionamide inside animals and humans.
Acrylamide is used in the plastic polymers industry for
water treatments and soil stabilization and to prepare polyacrylamide
gels for electrophoresis. This neurotoxic, carcinogenic,
and genotoxic substance is known to have caused
contact dermatitis in industrial and laboratory workers