A carboxyl-functional monomer for acrylic resins and methacrylate synthesis. It is used as a monomer and comonomer for acrylic resins and polymers and as an intermediate for methacrylate esters.
▸Acrylic resins: Monomer and comonomer for plastics and polymers.
▸Ester intermediate: Feedstock for methacrylate esters.
▸Functional comonomer: Carboxyl functionality for adhesion and dispersion stability.
▸Dispersions: Comonomer in latex and polymer dispersions.
Physical Properties
Physical Description
Methacrylic acid, stabilized appears as a clear colorless liquid with a pungent odor. Corrosive to metals and tissue. Combustible. Flash point 77 °C. Melting point 16 °C. May polymerize if contaminated or heated. If polymerization takes place inside a closed container, the container may violently rupture. Less dense than water and is soluble in water. Vapors heavier than air. Used to make plastics
Appearance
Clear colorless liquid or colorless crystals
Odor
Acrid, repulsive odor
Boiling Point
163 °C at 760 mmHg
Melting Point
16 °C
Flash Point
67 °C (67 °C) (closed cup)
Solubility
≥ 100 mg/mL at 17 °C
Density
1.015 at 20 °C
Vapor Density
2.97
Vapor Pressure
0.65 mmHg at 20 °C; 1 mmHg at 25 °C
LogP
log Kow = 0.93
Henry's Law Constant
Henry's Law constant = 3.9X10-7 atm-cu m/mole at 25 °C
Autoignition Temperature
400 °C
Viscosity
1.38 mPa.s at 24 °C
Corrosivity
Forms corrosive liquid at melting point
Heat of Vaporization
0.418 kJ/mol at 101.3 kPa (760 mm Hg)
Surface Tension
0.0265 N/m
Polymerization
Hazardous polymerizaton may occur. Usually contains inhibitors to prevent polymerization. Polymerizaton may be caused by elevated temperature, oxidizers, peroxides, or sunlight.... Uninhibited monomer vapor may form polymer in vents and other confined spaces. /Methacrylic acid, inhibited/
Refractive Index
Index of refraction: 1.43143 at 20 °C/D
Dissociation Constants
pKa = 4.65
Safety & Handling
Full SDS available on request
A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.
DOT / UN Transport Classification
UN / DOT NumberUN 2531
Hazard Class / DivisionClass 8
Packing GroupII
Proper Shipping NameMethacrylic acid, stabilized
Transport classification per the UN Model Regulations / 49 CFR 172.101 Hazardous Materials Table. Confirm against the grade-specific SDS (Section 14) before shipping.
HS / Tariff Classification
🌐Harmonized System (HS) Code — 6-digit international heading
2916.13
Chapter 29
Organic chemicals
Heading 29.16
Internationally harmonized (WCO HS)
Subheading 2916.13
6-digit international code — national tariff line adds further digits
Methacrylic acid (CAS 79-41-4), an unsaturated carboxylic acid monomer. It is used as a monomer and comonomer for acrylic resins and polymers and as an intermediate for methacrylate esters. As a carboxyl-functional comonomer it imparts adhesion and stability in coatings, adhesives, and polymer dispersions.
Frequently Asked Questions
What is methacrylic acid used for?
Methacrylic acid (MAA, CAS 79-41-4) is an unsaturated carboxylic acid monomer. It is used as a monomer and comonomer for acrylic resins and polymers, as an intermediate for methacrylate esters, and as a carboxyl-functional comonomer that imparts adhesion and stability in coatings, adhesives, and latex/polymer dispersions.
What is methacrylic acid also known as?
Methacrylic acid is also called MAA, 2-methylpropenoic acid, 2-methyl-2-propenoic acid, and alpha-methacrylic acid; CAS 79-41-4, formula C4H6O2. It is distinct from methyl methacrylate (the ester). RawSource supplies the acid monomer in bulk.
Is methacrylic acid an acid, and what is its function as a comonomer?
Yes — methacrylic acid is an unsaturated carboxylic acid, so it carries a reactive carboxyl (-COOH) group plus a polymerizable vinyl group. As a comonomer it introduces carboxyl functionality that improves adhesion, crosslink sites, and dispersion stability in acrylic latexes and coatings.
What HS code and UN number apply to methacrylic acid?
Methacrylic acid classifies under HS 2916.13 (methacrylic acid and its salts) and is assigned UN 2531 (METHACRYLIC ACID) for transport. Because it is a polymerizable monomer it is supplied inhibited; RawSource ships in compliance with applicable DOT/IMDG rules with full documentation.
What is the cost of bulk methacrylic acid?
Bulk MAA pricing depends on volume, inhibitor/grade, packaging, and destination. We quote per order rather than publishing spot pricing — request a bulk quote and RawSource will return current pricing with a CoA and SDS for the lot.
Disclaimer. Information on this page — including properties, identifiers, hazard, transport (DOT/UN) and tariff (HS) classifications, and applications — is provided for general reference and is compiled from authoritative public sources (e.g. PubChem/ECHA, 49 CFR 172.101, the Harmonized Tariff Schedule). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot purchased governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim or advice. Always consult the current Safety Data Sheet (SDS) before handling, storage, transport or disposal, and confirm regulatory status, classification and suitability for your application and jurisdiction. Hazard, transport and tariff classifications must be verified for your specific shipment. RawSource makes no warranty, express or implied, and assumes no liability for use of this information. Trademarks. Third-party trademarks and brand names are the property of their respective owners; any reference is nominative — used only to identify a comparable product — and does not imply affiliation with, sponsorship by, or endorsement by the trademark owner.
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