2-Hydroxyethyl methacrylate

2-Hydroxyethyl Methacrylate (HEMA) is a super useful functional acrylic monomer because it has both a polymerizable double bond and a hydrophilic hydroxyl (-OH) group. That combo makes it gold in many industries.

Here’s where it’s mainly used:

 
1. Coatings & Paints
HEMA improves:

Adhesion to metal, glass, and plastics
Hardness and chemical resistance
Crosslinking ability (reacts with isocyanates, melamine resins, etc.)
Used in:

Automotive coatings
Industrial protective coatings
UV-curable coatings
Wood finishes
The –OH group allows further chemical reaction, giving tougher films.

 
2. Dental Materials
One of HEMA’s biggest markets.

Used in:

Dental adhesives & bonding agents
Composite resins
Dental sealants
Why?

Good penetration into dentin
Forms strong polymer networks
Compatible with hydrophilic tooth structure
 
3. Contact Lenses (Hydrogels)
HEMA is a classic monomer for soft contact lenses.

Properties it provides:

Water absorption
Softness and flexibility
Oxygen permeability (when copolymerized)
Poly(HEMA) hydrogels were among the first soft lens materials.

 
 4. Medical & Biomedical Polymers
Because it’s biocompatible when polymerized:

Used in:

Drug delivery hydrogels
Tissue engineering scaffolds
Wound dressings
Catheters and medical coatings
Hydrophilicity helps control water uptake and drug release.

 
5. Adhesives & Sealants
HEMA improves:

Wetting of surfaces
Adhesion to polar substrates
Flexibility + strength balance
Common in:

Pressure-sensitive adhesives
Structural acrylic adhesives
 
6. Textile & Paper Treatments
Used to modify surfaces for:

Better dye uptake
Water absorbency
Improved coating adhesion
 
7. UV / Radiation Curing Systems
HEMA is used in:

UV inks
3D printing resins
Electronic coatings
The double bond polymerizes fast under UV.

 
 8. Copolymer Modifier
HEMA is often not used alone but to introduce –OH functionality into polymers like:

Acrylic resins
Styrene-acrylic emulsions
Polyester-modified systems
The hydroxyl group allows:

Crosslinking
Better pigment dispersion
Improved durability
 
Key Advantage Summary
Property
Benefit
Reactive double bond
Easy polymerization
Hydroxyl group
Crosslinking & adhesion
Hydrophilic
Water compatibility
Biocompatible polymer
Medical/dental use