Methacrylic acid (MAA, CH2=C(CH3)COOH) is a pungent liquid vinyl monomer carrying both a carboxyl group and a polymerizable double bond; it is used mainly as a comonomer to add reactive carboxyl functionality to acrylic resins and emulsion polymers, to provide crosslinking and adhesion, and to produce ion-exchange resins and specialty coatings.

What is methacrylic acid?

MAA is the simplest unsaturated methacrylic carboxylic acid, carrying a methyl group on the alpha carbon of acrylic acid. The molecule has two reactive sites: the vinyl double bond that takes part in free-radical polymerization, and the carboxyl group (-COOH) that enables neutralization, crosslinking and adhesion. At room temperature it is a colorless, pungent liquid that can form crystals on freezing at relatively low temperature.

Like all reactive monomers, MAA is prone to spontaneous polymerization, so the commercial product is usually stabilized with an inhibitor such as hydroquinone monomethyl ether (MEHQ) and stored cool with controlled oxygen contact.

Key applications of methacrylic acid

MAA's value comes from adding carboxyl functionality to a polymer chain. Key applications include:

  • Acrylic emulsion and solvent-based resins — a comonomer that improves adhesion, pigment dispersion and film stability in paints, coatings and adhesives.
  • Carboxylated acrylic and styrene-acrylic latexes for waterborne paints and paper coatings.
  • Ion-exchange resins — weakly acidic cation resins used in water treatment and purification.
  • Superabsorbent polymers, textile and leather finishing chemicals, flocculants and thickeners.
  • Raw material for methacrylate esters and specialty crosslinking/curing systems.
AKRİLİK REÇİNELERMethacrylic Acid (MAA)MAA in the KORKİMYA portfolio is offered as an inhibitor-stabilized monomer for acrylic resin and latex manufacturers.

Its function in acrylic resins

In acrylic formulations, MAA copolymerizes with acrylate/methacrylate esters and adds free carboxyl groups to the chain. Once neutralized, these groups provide dispersion and stability in waterborne systems, improve adhesion to metal surfaces and pigments, and react with external crosslinkers to raise film durability. The comonomer ratio sets the balance of acid value, hardness and water resistance in the finished resin.

Safe handling and storage

MAA is a corrosive, irritating acid that burns skin and eyes, and its vapor irritates the respiratory tract. It is also prone to polymerization: heat, light or loss of inhibitor can cause uncontrolled exothermic polymerization and pressure build-up. Maintain inhibitor levels, keep cool, vent containers and always follow the SDS.
  • Store in a cool, shaded, well-ventilated area within the recommended temperature range.
  • The inhibitor needs some dissolved oxygen to remain effective; avoid fully blanketing with inert gas (follow the SDS).
  • Keep away from ignition sources, oxidizers and polymerization initiators.
  • During long-term storage, monitor inhibitor level and freezing/crystallization.
What is methacrylic acid used for?

MAA is used mainly as a comonomer in acrylic resins and emulsion polymers, and also in ion-exchange resins, superabsorbent polymers, paper/textile chemicals and the production of methacrylate esters.

What is the difference between methacrylic acid and acrylic acid?

Methacrylic acid carries an extra methyl group on the alpha carbon of acrylic acid. That methyl group gives the resulting polymers a higher glass transition temperature, more hardness and better resistance to hydrolysis.

Why is methacrylic acid stored with an inhibitor?

MAA is a reactive vinyl monomer that can polymerize spontaneously with heat or light. An inhibitor such as MEHQ prevents uncontrolled exothermic polymerization during storage and transport.

Is methacrylic acid soluble in water?

Yes, methacrylic acid is miscible with water, forming an acidic solution, and is also soluble in many organic solvents.