METHACRYLIC ACID

Methacrylic acid, abbreviated MAA, is an organic compound. This colorless, viscous liquid is a carboxylic acid with an acrid unpleasant odor. It is soluble in warm water and miscible with most organic solvents. Methacrylic acid is produced industrially on a large scale as a precursor to its esters, especially methyl methacrylate (MMA), and to poly(methyl methacrylate) (PMMA).

IUPAC name: 2-Methylprop-2-enoic acid
CAS Number: 79-41-4
EC Number: 201-204-4
Chemical formula: C4H6O2

Production of Methacrylic acid:
In the most common route, methacrylic acid is prepared from acetone cyanohydrin, which is converted to methacrylamide sulfate using sulfuric acid.
This derivative in turn is hydrolyzed to methacrylic acid, or esterified to methyl methacrylate in one step.

Another route to methacrylic acid starts with isobutylene, which obtainable by dehydration of tert-butanol.
Isobutylene is oxidized sequentially to methacrolein and then methacrylic acid.
Methacrolein for this purpose can also be obtained from formaldehyde and ethylene.
Yet a third route involves the dehydrogenation of Isobutyric acid.

Various green routes have been explored but they have not been commercialized.
Specifically, the decarboxylation of itaconic acid, citraconic acid, and mesaconic acids affords methacrylic acid.
Salts of methacrylic acid have been obtained by boiling citra- or meso-brompyrotartaric acids with alkalis.
Pyrolysis of ethyl methacrylate efficiently gives methacrylic acid.

Uses and occurrence of Methacrylic acid:
Of course, the main use of MMA is its polymerization to poly(methyl methacrylate).
Methacrylic acid is used in some nail primers to help acrylic nails adhere to the nail plate.
MAA occurs naturally in small amounts in the oil of Roman chamomile.

Reactions of Methacrylic acid:
For a commercial applications, MMA is polymerized using azobisisobutyronitrile as a thermally activated free-radical catalyst.
Otherwise, MMA is relatively slow to polymerize thermally or photochemically.
Methacrylic acid undergoes several reactions characteristic of alpha,beta-unsaturated acids.
These reactions include Diels-Alder reaction and Michael additions.

Esterifications are effected by acid-catalyzed condensations with alcohols, alkylations with certain alkenes, and transesterifications.
Epoxide ring-opening gives hydroxyalkyl esters.
Sodium amalgam reduces it to isobutyric acid.
A polymeric form of methacrylic acid was described in 1880.

Consumer Uses of Methacrylic acid:
Methacrylic acid is used in the following products: adhesives and sealants.
Other release to the environment of Methacrylic acid is likely to occur from: outdoor use, indoor use (e.g. machine wash liquids/detergents, automotive care products, paints and coating or adhesives, fragrances and air fresheners) and indoor use in close systems with minimal release (e.g. cooling liquids in refrigerators, oil-based electric heaters).

Service life of Methacrylic acid:
Other release to the environment of Methacrylic acid is likely to occur from: outdoor use in long-life materials with low release rate (e.g. metal, wooden and plastic construction and building materials) and indoor use in long-life materials with low release rate (e.g. flooring, furniture, toys, construction materials, curtains, foot-wear, leather products, paper and cardboard products, electronic equipment).

Methacrylic acid can be found in complex articles, with no release intended: vehicles, machinery, mechanical appliances and electrical/electronic products (e.g. computers, cameras, lamps, refrigerators, washing machines) and electrical batteries and accumulators.

Methacrylic acid can be found in products with material based on: plastic (e.g. food packaging and storage, toys, mobile phones), rubber (e.g. tyres, shoes, toys), stone, plaster, cement, glass or ceramic (e.g. dishes, pots/pans, food storage containers, construction and isolation material), fabrics, textiles and apparel (e.g. clothing, mattress, curtains or carpets, textile toys), leather (e.g. gloves, shoes, purses, furniture), metal (e.g. cutlery, pots, toys, jewellery), paper (e.g. tissues, feminine hygiene products, nappies, books, magazines, wallpaper) and wood (e.g. floors, furniture, toys).

Widespread uses by professional workers:
Methacrylic acid is used in the following products: inks and toners, coating products, polymers, adhesives and sealants, non-metal-surface treatment products, paper chemicals and dyes and washing & cleaning products.
Methacrylic acid has an industrial use resulting in manufacture of another substance (use of intermediates).

Methacrylic acid is used in the following areas: building & construction work, printing and recorded media reproduction and scientific research and development.
Methacrylic acid is used for the manufacture of: plastic products and electrical, electronic and optical equipment.
Other release to the environment of Methacrylic acid is likely to occur from: outdoor use and indoor use (e.g. machine wash liquids/detergents, automotive care products, paints and coating or adhesives, fragrances and air fresheners).

Formulation or re-packing of Methacrylic acid:
Methacrylic acid is used in the following products: polymers, non-metal-surface treatment products, inks and toners, laboratory chemicals, paper chemicals and dyes and washing & cleaning products.
Methacrylic acid has an industrial use resulting in manufacture of another substance (use of intermediates).
Release to the environment of Methacrylic acid can occur from industrial use: formulation of mixtures and formulation in materials.

Uses at industrial sites
Methacrylic acid is used in the following products: polymers, coating products, inks and toners and adhesives and sealants.
Methacrylic acid has an industrial use resulting in manufacture of another substance (use of intermediates).
Methacrylic acid is used for the manufacture of: chemicals and plastic products.
Release to the environment of Methacrylic acid can occur from industrial use: for thermoplastic manufacture, as an intermediate step in further manufacturing of another substance (use of intermediates) and in the production of articles.

Manufacture of Methacrylic acid:
Release to the environment of Methacrylic acid can occur from industrial use: manufacturing of the substance, in processing aids at industrial sites, in the production of articles, as an intermediate step in further manufacturing of another substance (use of intermediates), as processing aid, for thermoplastic manufacture, as processing aid and of substances in closed systems with minimal release.

Molar mass: 86.09 g/mol
Appearance: Colorless liquid or solid
Odor: Acrid, repulsive
Density: 1.015 g/cm3

Melting point: 14 to 15 °C
Boiling point: 161 °C
Solubility in water: 9% (25 °C)

Vapor pressure: 0.7 mmHg (20 °C
XLogP3    0.9:
Hydrogen Bond Donor Count: 1
Hydrogen Bond Acceptor Count: 2

Rotatable Bond Count: 1
Exact Mass: 86.036779430
Monoisotopic Mass: 86.036779430
Topological Polar Surface Area: 37.3 Ų

Heavy Atom Count: 6
Complexity: 83.5
Isotope Atom Count: 0
Defined Atom Stereocenter Count: 0

Undefined Atom Stereocenter Count: 0
Defined Bond Stereocenter Count: 0
Undefined Bond Stereocenter Count: 0
Covalently-Bonded Unit Count: 1
Compound Is Canonicalized: Yes

Methacrylic acid appears as a clear colorless liquid (or low-melting solid) with a pungent odor. Corrosive to metals and tissue.
Flash point 170 °F.
Melting point 61 °F.
May polymerize exothermically if heated or contaminated.
If the polymerization takes place inside a container, the container may rupture violently.
Less dense than water.
Vapors heavier than air.
Used to make plastics.

Methacrylic acid is an alpha,beta-unsaturated monocarboxylic acid that is acrylic acid in which the hydrogen at position 2 is substituted by a methyl group.
It is functionally related to an acrylic acid.
It is a conjugate acid of a methacrylate.

Applications of Methacrylic acid: 
Paint
Adhesive
Fiber processing agent
Rubber modifier
Leather treatment
Paper processing agent
Lubricant additive
Cement mixing agent

Methacrylic acid is used in chemistry as a stabilizing agent, forming a thin capping layer on the surface of nanoparticles.
Methacrylic acid is also used as a surfactant, so that control is maintained during nanocrystal growth.
Methacrylic acid is also used as a chelating agent.

Methacrylic acid (MAA) is a polymerizable, unsaturated, monocarboxylic acid functional monomer.
In copolymers, low levels (≤5%) of Methacrylic acid improve latex stability, adhesive properties,  wettability and pigment dispersion, as well as allowing for post-crosslinking reactions.
At higher levels of Methacrylic acid, copolymers are used as thickening agents and rheology modifiers, paper coatings, personal care products, oil field chemicals, processing agents and water-soluble polymers.  

Methacrylic acid is a clear, colorless liquid with a molecular weight of 86.06 g/mol, a freeze point of ca. 14 °C, a boiling point of 161 °C, and a viscosity of 1.5.

Methacrylic acid is used in copolymers to enhance performance in adhesives, caulks, sealants, paint, coatings, varnishes, printing inks, and textile finishes.
Higher levels of Methacrylic acid are used in copolymers for applications such as thickeners, dispersants, wetting agents, and flocculants. 
Virtually all acrylic copolymers produced commercially contain one of two key monomers

Methacrylic acid is most often produced from acetone and HCN in a so called ACH process.
Methacrylic acid can also be produced from isobutylene by a two-step oxidation process. 

MMA is supplied containing a polymerization inhibitor, MEHQ.  MMA will readily self-polymerize if not properly inhibited, stored, and handled.  Polymerization can be rapid and violent, generating large amounts of heat and pressure.  Note that it is important to store these stabilized monomers under an air atmosphere and to replenish oxygen over time in order for inhibitors like MEHQ to effectively function.

Methacrylic acid requires special attention to avoid freezing because the crystallized monomer excludes the inhibitor, and the solid will contain a deficiency of inhibitor and oxygen.
During thawing process the contents must be mixed in order to redistribute the inhibitor and resupply dissolved oxygen.
Temperatures must be limited to 35-45 °C.
Unlike GAA, Methacrylic acid does not form a thermal dimer over time. 
An intercompany committee prepared an excellent reference manual on the safe handling and storage of inhibited Methacrylic acid.

Methacrylic acid is an alpha,beta-unsaturated monocarboxylic acid that is acrylic acid in which the hydrogen at position 2 is substituted by a methyl group.Methacrylic acid appears as a clear colorless liquid (or low-melting solid) with a pungent odor.

Preparation Method of Methacrylic acid:
Acetone cyanohydrin method acetone and hydrocyanic acid are reacted in the presence of an alkali catalyst to generate acetone cyanohydrin, and then reacted with concentrated sulfuric acid to generate methacrylamide sulfate, which is then hydrolyzed to generate methacrylic acid.
Acetone cyanohydrin and sulfuric acid are required to contain no water in the production, otherwise acetone or methyl isobutyrate will be left in the product, which will affect the quality of the product.

Isobutylene oxidation isobutylene is oxidized in two steps, methacrolein is generated in the first step, methacrylic acid is generated in the second step, and then a qualified product is obtained by rectification.
Tert-butanol may also be used instead of isobutene.
the hydrolysis method of methacrylonitrile is obtained by using isobutylene as a raw material through ammonia oxygen and hydrolysis.
methacrolein is prepared by isobutane oxidation through oxidation, and then obtained by oxidation.;

Uses of Methacrylic acid:
Important organic chemical raw materials and polymer intermediates. Its most important derivatives of methyl methacrylate production of organic glass can be used in aircraft and civil building windows, can also be processed into buttons, solar filters and automotive light lenses; the produced coating has superior suspension, Rheology and durability properties; The prepared binder can be used for the adhesion of metal, leather, plastic and building materials; Methacrylate polymer emulsion is used as fabric finishing agent and antistatic agent. In addition, methacrylic acid can also be used as a raw material for synthetic rubber.

Safety of Methacrylic acid:
Methacrylic acid has moderate toxicity, strong irritation to the skin and mucous membranes, rats by mouth ld508400 mg/kg.
But found no carcinogenic phenomenon.
The allowable limit concentration in the workplace is 100 × 10-6 (temporary working area).
Good ventilation conditions are required in the production workshop, and the operator should wear protective equipment, especially protective goggles.

Rinse with plenty of water when touching the skin.
packed in polyethylene-lined aluminum or glass and stainless steel containers with a net weight of 200kg. The storage period is about three months.
When thawing, the thawing temperature should be about 25 ° C at room temperature, and it can be used after complete melting and mixing.
The hazardous materials shall be stored and transported according to the regulations.

Methacrylic acid is an important chemical raw material, which has two functional groups of carbon-carbon double bond and carboxylic acid group, thus, polymerization, esterification and the like can be carried out.
Methacrylic acid can be used for the preparation of methyl methacrylate, coatings, synthetic rubber, adhesives, fabric treatment agents, resins, polymer additives and functional polymer materials.

Used in the manufacture of coatings, insulating materials, binders and ion exchange resins
important organic chemical raw materials and polymer intermediates.
Its most important derivatives of methyl methacrylate production of organic glass can be used in aircraft and civil building windows, can also be processed into buttons, solar filters and automotive light lenses; the coatings produced have superior suspension, Rheology and durability properties; The resulting binders are useful for bonding metals, leather, plastics and building materials; And the methacrylate polymer emulsions are used as fabric finishes and antistatic agents. In addition, methacrylic acid can also be used as a raw material for synthetic rubber.
use as an organic reagent
production of resins, plastics, high-molecular polymers, and production of esters.

There are two main industrial production methods of methacrylic acid, that is, acetone cyanohydrin method is isobutylene (tert-butyl alcohol) oxidation method.
Acetone cyanohydrin method acetone and hydrocyanic acid in the presence of alkali catalyst, reaction to generate acetone cyanohydrin, and then react with concentrated sulfuric acid to generate methacrylamide sulfate, and then by hydrolysis to generate methacrylic acid.
Acetone cyanohydrin and sulfuric acid are required to contain no water in the production, otherwise acetone or α-hydroxyisobutyrate will be produced and remain in the product, which will affect the product quality.

The production of methacrylic acid by acetone cyanohydrin method consumes 898kg of sodium cyanide (>87%), 1100kg of acetone (98.5%) and 4080kg of sulfuric acid (fuming) per ton of product.
Isobutylene (tert-butyl alcohol) oxidation isobutylene is oxidized in two steps, the first step generates methacrolein, the second step generates methacrylic acid, and then the qualified product is obtained by distillation.
Methacrylonitrile hydrolysis method with isobutylene as raw material, ammonia oxygen, hydrolysis and derived.
Isobutane oxidation by oxidation of methacrolein, and then obtained by oxidation.

Methacrylic Acid is a functional monomer, an unsaturated monocarboxylic acid.
Methacrylic Acid reacts as a vinyl compound and as a carboxylic acid.
Methacrylic Acid easily undergoes polymerization and addition reactions.
The copolymers of Methacrylic Acid can be prepared with acrylic and methacrylic esters, acrylonitrile, maleic acid esters, vinyl acetate, vinyl chloride, vinylidene chloride, styrene, butadiene, ethylene, and other monomers.

Methacrylic Acid, also known as MAA, Acrylic Acid, or 2-Propenoic acid, 2-methyl- is an organic compound with the formula C4H602.
It's clear, colorless, volatile liquid with a characteristic odor.
Methacrylic Acid is slightly soluble in warm water and miscible with most organic solvents.
Undiluted or glacial methacrylic acid is produced for use a building block to make a wide range of polymer-based products like binders in paints and coatings but also water-soluble polymers, as an interlevant in glass and, as an intermediate for the manufacture of methacrylic acid esters.

Other names:
79-41-4
2-Propenoic acid, 2-methyl-
2-Methylacrylic acid
2-methylprop-2-enoic acid
Methylacrylic acid
2-Methylpropenoic acid
2-Methyl-2-propenoic acid
alpha-Methylacrylic acid
2-Methylenepropionic acid
Acrylic acid, 2-methyl-
alpha-Methacrylic acid
Propionic acid, 2-methylene-
Kyselina methakrylova
Methacrylsaeure
Methakrylsaeure
NSC 7393
25087-26-7
2-Methylpropensaeure
2-Methyl-acrylic acid
.alpha.-Methacrylic acid
.alpha.-Methylacrylic acid
CHEBI:25219
NSC-7393
1CS02G8656
2-Methacrylic Acid
methacrylicacid
Propenoic acid, 2-methyl
Acido metacrilico
Acide methacrylique
CCRIS 5925
HSDB 2649
EINECS 201-204-4
UN2531
BRN 1719937
AI3-15724
UNII-1CS02G8656
Methyl acrylic acid
GMAA Methacrylic Acid
Methacrylic acid glacial
Methacrylic acid monomer
Glacial Methacrylic Acid
METHACRYLIC AC ID
CH2=C(CH3)COOH
EC 201-204-4
WLN: QVY1&U1
4-02-00-01518
CHEMBL1213531
DTXSID3025542
NSC7393
STR02118
ZINC1683524
Tox21_200826
BBL011616
MFCD00002651
STL163339
AKOS000121138
CAS-79-41-4
NCGC00248843-01
NCGC00258380-01
BP-30227
FT-0613003
M0079
EN300-24829
Q165949
J-521686
25068-55-7