Methacrylic Acid, Methlacrylic Acid, MAA, 79-41-4 

Methacrylic Acid, Methlacrylic Acid, MAA, 79-41-4

METHACRYLIC ACID (MAA)

Methacrylic Acid / Methylacrylic Acid / 2-Methylacrylic Acid / α-Methylacrylic Acid / 2-Methylpropenoic Acid
CAS Number: 79-41-4
EC Number: 201-204-4

1. IDENTIFICATION INFORMATION

2. PHYSICAL PROPERTIES

3. CHEMICAL PROPERTIES

Polymerization Reaction:

n CH₂=C(CH₃)-COOH → [CH₂-C(CH₃)(COOH)]n (Polymethacrylic acid)

Esterification Reaction (Methyl Methacrylate Production):

CH₂=C(CH₃)-COOH + CH₃OH → CH₂=C(CH₃)-COOCH₃ + H₂O

4. PRODUCTION PROCESS

Reaction Equations:

Acetone Cyanohydrin Method:

(CH₃)₂CO + HCN → (CH₃)₂C(OH)CN
(CH₃)₂C(OH)CN + H₂SO₄ → CH₂=C(CH₃)-CONH₂·H₂SO₄
CH₂=C(CH₃)-CONH₂·H₂SO₄ + H₂O → CH₂=C(CH₃)-COOH + (NH₄)₂SO₄

Isobutylene Oxidation (Most Common):

(CH₃)₂C=CH₂ + O₂  —[Catalyst]—> CH₂=C(CH₃)-CHO (Methacrolein) + H₂O
CH₂=C(CH₃)-CHO + 0.5 O₂ —[Catalyst]—> CH₂=C(CH₃)-COOH

5. AVAILABLE FORMS AND SPECIFICATIONS

Typical Specifications (Stabilized Grade):

6. APPLICATIONS

6.1. Methyl Methacrylate (MMA) Production – Largest Use (~60%)

6.2. Methacrylate Esters Production

6.3. Coatings and Paints

6.4. Adhesives and Binders

6.5. Polymer Emulsions and Textile Finishing

6.6. Synthetic Rubber

6.7. Ion Exchange Resins

6.8. Polymer Additives and Functional Materials

6.9. Insulating Materials

6.10. Other Applications

7. DERIVATIVES AND DOWNSTREAM PRODUCTS

8. QUALITY SPECIFICATIONS (Industrial Grade)

9. STORAGE AND HANDLING

Handling Notes:

• Must contain stabilizer (MEHQ or hydroquinone) to prevent polymerization

• In the absence of stabilizer, will readily polymerize (exothermic, potentially explosive)

• Solidifies below 12-16°C; thaw at room temperature (approx. 25°C) – do not overheat

• Use only stainless steel or glass equipment; avoid copper, brass, or iron

• Keep away from heat, sparks, and open flames

• Use explosion-proof electrical equipment

• Ensure good ventilation

• Use with adequate personal protective equipment

10. SAFETY AND HEALTH INFORMATION (GHS CLASSIFICATION)

11. HAZARD STATEMENTS (H-CODES)

12. SAFETY STATEMENTS (P-CODES)

13. TOXICOLOGICAL INFORMATION

Health Effects:

Occupational Exposure Limits:

14. FIRST AID MEASURES

15. FIRE FIGHTING MEASURES

16. ENVIRONMENTAL INFORMATION

17. TRANSPORT INFORMATION

18. REGULATORY INFORMATION

EINECS: 201-204-4

RTECS: OZ2975000

HS Code: 2916 13 00

19. OTHER NAMES AND SYNONYMS

Database Identifiers:

20. SUMMARY AND IMPORTANT WARNINGS

SUMMARY:

Methacrylic acid (MAA, C₄H₆O₂, CAS 79-41-4) is a colorless clear liquid with a repulsive, acrid odor. It contains both a carboxylic acid group and a vinyl double bond, making it a versatile monomer and chemical intermediate. It has a melting point of 12-16°C and boiling point of 163°C. Methacrylic acid is stabilized with MEHQ (250 ppm) or hydroquinone to prevent premature polymerization. The largest application (~60%) is the production of methyl methacrylate (MMA) for organic glass (Plexiglas). Other applications include methacrylate esters, coatings, adhesives, polymer emulsions, synthetic rubber, ion exchange resins, and functional polymers.

Key Properties:

Main Application Areas:

Key Safety Points:

• CORROSIVE: Causes severe skin burns and eye damage (H314, H318)

• HARMFUL: Harmful if swallowed, in contact with skin, or if inhaled (H302, H312, H332)

• POLYMERIZATION HAZARD: Readily polymerizes without stabilizer; can be explosive

• COMBUSTIBLE: Flash point 77°C; can form explosive mixtures with air (1.6-8.7%)

• USE STABILIZER: Do not use without MEHQ or hydroquinone

• USE PPE: Chemical goggles, face shield, acid-resistant gloves (neoprene, nitrile), protective clothing

• USE VENTILATION: Work in fume hood or well-ventilated area

• STORAGE: 15-25°C; do not freeze (solidifies below 12-16°C)

IMPORTANT WARNINGS:

Polymerization Hazard: Methacrylic acid readily polymerizes in the absence of a stabilizer. Polymerization is exothermic and can become explosive, especially in closed containers. MUST contain MEHQ (250 ppm) or hydroquinone as stabilizer. Never use unstabilized methacrylic acid. High temperatures, light, peroxides, and polymerization initiators can trigger polymerization.

Corrosive Properties: Methacrylic acid is corrosive and causes severe skin burns and eye damage. Use appropriate personal protective equipment including chemical goggles, face shield, acid-resistant gloves, and protective clothing.

Solidification: Methacrylic acid solidifies below 12-16°C. If frozen, thaw at room temperature (approx. 25°C). Do not overheat; do not use direct flame or steam to thaw.

Storage: Store at room temperature (15-25°C). DO NOT FREEZE. Store away from heat, light, strong oxidizing agents, strong bases, amines, peroxides, and polymerization initiators. Store in polyethylene-lined aluminum, glass, or stainless steel containers. Avoid copper, brass, or iron equipment.

Combustible Liquid: Flash point 77°C. Can form explosive mixtures with air (explosive limit 1.6-8.7%). Use explosion-proof electrical equipment. Keep away from heat, sparks, and open flames.

Methyl Methacrylate (MMA): The most important derivative of methacrylic acid is methyl methacrylate (MMA), which is used to produce organic glass (Plexiglas). MMA polymer is known for its optical clarity, weather resistance, and durability, making it suitable for aircraft windows, automotive light lenses, solar filters, and buttons.

Coatings: Methacrylic acid-based coatings have superior suspension properties, rheology control, and durability. They are used in automotive topcoats, industrial coatings, and waterborne paints.

Ion Exchange Resins: Methacrylic acid is used in the production of cation exchange resins for water softening and demineralization.

Biomedical Applications: Methacrylate derivatives such as HEMA (hydroxyethyl methacrylate) are used in contact lenses, hydrogels, drug delivery systems, and bone cements.

Flammable Limits: Lower explosive limit 1.6%, upper explosive limit 8.7%. Vapors are heavier than air and may travel along the ground to ignition sources.

Important Disclaimer: This Technical Data Sheet (TDS) is for informational purposes only. For complete safety, handling, storage, and regulatory compliance information, always refer to the official Safety Data Sheet (SDS) provided by the manufacturer/supplier. Methacrylic acid MUST be stored and handled with a stabilizer (MEHQ or hydroquinone). Never use unstabilized material. In case of polymerization, evacuate area immediately.