Petrochemical Blog

5 Key Facts on Methyl Methacrylate Monomer (MMA)

published on September 21, 2017

Methyl methacrylate (MMA) is a monomer that’s also known as methacrylic acid, methyl ester.

A key building block for acrylic-based polymers, MMA has applications that include safety glazing, exterior paints, vinyl impact modifiers, adhesives, illuminated light displays, and more.   

In this article, we provide a general overview of this important monomer, covering everything from its polymerization to important safety and handling considerations.

Here are 5 key facts on methyl methacrylate:

1. The Basics of Methyl Methacrylate

As previously mentioned, MMA is foundational for many acrylate polymers and is an essential comonomer in paint, coatings, and adhesives resin formulations. In free radical initiated copolymers, MMA elevates the Tg (glass transition) and contributes durability, strength, transparency, and UV and abrasion resistance.

The chemical structure of MMA is shown below.

methyl-methacrylate-mma.png

Here are several other key pieces of information about methyl methacrylate:

CAS Number 80-62-6
EINECS Number 201-297-1
Empirical Formula C5H8O2
Molecular Weight 100.12
Melting Point -48 °C  (-54℉)
Boiling Point 101°C   (214℉)
Flash Point 2°C  (36℉)

Additionally, it’s important to note that the Tg value for PMMA homopolymer is 105°C. In polymers, MMA contributes durability, hardness, impact strength, scratch resistance, and clarity.

2. The Polymerization of MMA

When it comes to polymerization, the range of acrylic copolymers that can be used with MMA is extensive. Monomer feeds can include...

  • Butyl acrylate.
  • 2-Ethylhexyl acrylate.
  • Methyl methacrylate and other methacrylate esters.   
  • Acrylic acid and methacrylic acid.
  • Styrene.
  • Butadiene.

The monomer composition selected for copolymers is driven by the desired Tg of the resin, ranging from -30˚C to > 30˚C. The free-radical reactivity ratios for MMA copolymer systems have been well studied and are available in the literature.

For reference Tg values of some comonomers, please consult the table below.  

AA

Sty.

MMA

BA

2-EHA

87˚C

100˚C

105˚C

-45˚C

-55˚C


3. The Applications of Methyl Methacrylate

Methyl methacrylate monomer readily polymerizes to form high molecular weight homopolymers and copolymers.

The principal use for MMA monomer is to form polymethyl methacrylate (PMMA) homopolymer for the production of cast and extruded acrylic sheets. These cast PMMA sheeting products exhibit good optical clarity, high transparency, and UV stability. Applications include…

  • Shatterproof glass replacements.
  • Safety glazing.
  • Panels and lighting displays.
  • Outdoor lighting fixtures.
  • Plumbing fixtures and components.

Outside of glazing and sheet applications, the largest use for MMA is as a comonomer in paints and coatings, such as exterior paints and paper coatings. Polymers and copolymers of methyl methacrylate are in…

  • Metal and foil coatings.
  • Industrial finishes.
  • Floor polishes.
  • Textile finishes.
  • Adhesives.
  • Sealants.
  • Construction materials.
  • PVC impact modifiers.
  • Packaging.
  • Inks.  

These polymers are produced as waterborne, solvent, and dispersion resins for these applications. Methyl methacrylate-butadiene-styrene (MBS) resins are used as impact modifiers for clear, rigid PVC, an example of which would be bottles. In addition, MMA can partially replace styrene monomer in unsaturated polyester resins to give better weather resistance and longer outdoor life.

For products such as signage, displays, bath enclosures, spas and tabletop surfaces, as well as automotive lights and light fixtures, MMA polymerization can be cast into a solid form.

Applications also include engineering adhesives. These are liquid, reactive, durable adhesives for bonding a variety of substrates, and they consist of MMA monomer with PMMA. Low-viscosity, rapidly curing MMA reactive resin systems are highly effective for sealing and filling cracks and pores in concrete surfaces and structures.  

Other MMA copolymer applications include mining flocculants, soil stabilization polymers, waterproofing agents, and oil field drilling fluids.

4. The Composition of a Methyl Methacrylate Emulsion

To provide an example of a methyl methacrylate application, we’ve included an example of an emulsion composition involving MMA.

Below is a typical paint formulation using MMA monomer in a copolymer.

Composition Reactor

Deionized water

90.9 g 


Momer Feed System A

Deionized water

372.0 g

Rhodapex CO-436

8.2 g (1 weight %/polymer)

Acrylic acid (GAA)

4.6 g (0.9 weight %/polymer)

Styrene (St)

74.6 g (15.1 weight %/polymer)

Methyl methacrylate (MMA)

80.3 g (16.3 weight %/polymer)

Butyl acrylate (BA)

195.2 g (39.5 weight %/polymer)

2-EHA (EHA)

129.6 g  (26.3 weight %/polymer)

   

Subtotal

(873.9 g)


Initiator Feed System B

Deionized water

34.6 g

Ammonium Persulfate

1.46 g (0.3 weight %/polymer)

   

Subtotal

(36.1 g)

   

Total

1,000.0 g


Emulsion/Polymer Characteristic

Tg (Measured value)

-12˚C

Viscosity

99 mPa.s

Nonvolatile substance, ca

0.50%

Acid value

7.2 mg KOH/g

Particle size

0.22 μm

pH

9.0 (Ammonia)



5. Safety and Handling for MMA

Giving proper attention to safety is critical when handling methyl methacrylate for several reasons.

MMA is a flammable, colorless liquid which melts at -48˚C and boils at 101˚C. While MMA is soluble in the most organic solvents, it is insoluble in water.

In addition to being flammable, direct contact with MMA can cause irritation of the eyes, skin, nose, and throat. Considered a skin sensitizer, methyl methacrylate can produce allergic reactions from contact, in which future exposures can cause itching and a skin rash.

Even more seriously, inhalation of MMA vapor or mist can cause irritation of the nose, throat, and lungs and can be fatal in high concentrations.

Because MMA can violently homo-polymerize and can generate considerable heat and pressure, MMA is only provided in a stabilized form. To ensure MMA’s stabilizer can function effectively, it’s important to store MMA under air and replenish the dissolved oxygen.  

To obtain a Safety Data Sheet (SDS) and other handling information on MMA, please contact us or call us. At Gantrade Corporation, we encourage our customers to have a comprehensive understanding of the health, safety, environmental, and regulatory information on our products before handling.

How to Purchase High-Purity MMA

If you’re looking to purchase high-purity MMA, Gantrade Corporation provides this monomer in 20 MT (44,080 lb.) for industrial use only.

The purity of our methyl methacrylate is ≥ 99.9%, and our MMA contains only traces of water (0.035% max.) and acidity as methacrylic acid (0.0035% max.).

For storage and transportation, we’ve added an inhibitor, usually 15-18 ppm of Topanol A, which is FDA compliant and nonstaining and exhibits low volatility.

If you have questions about substituting Topanol for MEHQ or commingling Topanol-stabilized MMA with MEHQ-stabilized MMA, simply contact us, and we’d be happy to answer your questions.

Below is a table containing Gantrade’s specifications for methyl methacrylate.  

Sale Specifications: MMA

Item

Specifications

Appearance at 25 °C

Clear, colorless liquid

Purity by GC, %

99.9

Color, Pt-Co

≤ 5

Moisture weight % by K.F.

≤0.02

Inhibitor Concentration,

ppm Topanol A

15-18

Acidity, %

≤0.0035


Whether you have questions about the properties of methyl methacrylate or you want additional information about Gantrade’s product offerings, contact Gantrade to speak with us about your specific needs.

Topics: Technical

Subscribe to Email Updates

Recent Posts