HEMA

HEMA
Name	2-Hydroxyethyl methacrylate
Caption	Structural formula of 2-hydroxyethyl methacrylate
Othernames	2-HEMA; HEMAc; hydroxyethyl methacrylate
Formula	C6H10O3
Molar mass	130.14 g·mol−1
CAS number	868-77-9
Density	1.07 g·cm−3
Melting point	−20 °C
Boiling point	212–214 °C
Solubility	miscible with water, ethanol, acetone

HEMA

2-Hydroxyethyl methacrylate is a methacrylate monomer widely used in polymer chemistry, adhesives, coatings, and biomaterials. It serves as a hydrophilic monomer for producing crosslinked and linear polymers and finds applications spanning DuPont, 3M, Bayer, Sigma-Aldrich, and biomedical manufacturers such as Ivoclar Vivadent and Dentsply Sirona. The compound’s reactivity, volatility, and biocompatibility profile have driven extensive study across industrial, dental, and regulatory contexts involving agencies like U.S. Food and Drug Administration, European Chemicals Agency, and Occupational Safety and Health Administration.

Etymology and Terminology

The systematic name 2-hydroxyethyl methacrylate reflects IUPAC conventions similar to nomenclature used for monomers like methyl methacrylate and ethyl acrylate, while trade names (for example, those marketed by BASF or Evonik) often appear alongside abbreviations such as 2-HEMA or HEMAc used in patents from firms like Dow Chemical Company and research by institutions including Max Planck Society. Historical development traces to polymer chemistry advances at laboratories associated with DuPont and polymer pioneers such as Wallace H. Carothers-era successors who expanded methacrylate chemistry used in products from Rhodia to AkzoNobel.

Chemical Structure and Properties

The molecule contains a methacrylate vinyl group linked to a 2-hydroxyethyl side chain, analogous in backbone reactivity to monomers like methyl methacrylate and glycidyl methacrylate. Its hydroxyl functionality confers hydrophilicity comparable to monomers used by BASF in hydrogel formulations and supports hydrogen bonding similar to compounds studied at Max Planck Institute for Polymer Research. Typical radical polymerization initiators include peroxides and azo compounds commercialized by Wacker Chemie and AkzoNobel. Physical properties—liquid state at ambient temperature, moderate vapor pressure, and miscibility with solvents sold by Merck and Sigma-Aldrich—inform handling protocols developed by Occupational Safety and Health Administration and laboratories such as those at MIT and Stanford University.

Production and Industrial Applications

Industrial synthesis routes mirror methacrylate manufacture developed by companies like ROHM and HAAS and involve esterification of methacrylic acid (produced by entities such as Lonza and Arkema) with ethylene glycol; catalysts and processes researched at Imperial Chemical Industries subsidiaries optimize yield. Commercial uses encompass formulation of contact lens hydrogels by firms like Johnson & Johnson Vision Care and CooperVision, dental resin systems produced by 3M and Ivoclar Vivadent, UV-curable coatings from suppliers including Henkel and BASF, and acrylic adhesives used by Loctite (a Henkel brand). Copolymers with N-vinylpyrrolidone or methyl methacrylate appear in medical devices and optical materials from manufacturers such as EssilorLuxottica and research centers like Fraunhofer Society.

Medical and Dental Uses

In dentistry, the monomer functions as an adhesive primer and resin component in restorative systems developed by Dentsply Sirona, Kerr Corporation, and 3M ESPE; it enhances bond strength between composite materials and tooth substrates, a concept investigated at dental schools like King’s College London and University of Gothenburg. Ophthalmic applications include soft hydrogel contact lenses researched at Harvard Medical School and commercialized by Alcon and Bausch & Lomb. Biomedical research into tissue engineering and drug delivery incorporates poly(2-hydroxyethyl methacrylate) hydrogels studied by groups at Johns Hopkins University and University of California, Berkeley for controlled-release matrices and scaffolds.

Safety, Toxicity, and Regulatory Status

Toxicological profiles evaluated by regulatory bodies such as European Chemicals Agency and U.S. Environmental Protection Agency indicate skin and eye irritation potential and sensitization risks noted in assessments by Occupational Safety and Health Administration. Occupational exposure limits and guidance have been issued informed by toxicology studies from institutes like National Institute for Occupational Safety and Health and Health Canada. Clinical reports in dental literature from clinics affiliated with Mayo Clinic and Cleveland Clinic describe contact dermatitis and allergic reactions linked to residual monomer; manufacturers including Ivoclar Vivadent publish material safety data sheets recommending protective measures. Restrictions, classification, and labeling measures reflect chemical safety frameworks administered by REACH authorities and national agencies including FDA oversight for medical devices incorporating cured polymers.

Environmental Impact and Degradation

Environmental fate studies by research groups at Utrecht University and ETH Zurich examine hydrolysis, photodegradation, and microbial breakdown pathways similar to those documented for other methacrylates investigated by European Commission Joint Research Centre. Aquatic toxicity data submitted to regulatory bodies show variable effects on aquatic invertebrates and algae, comparable to datasets for methyl methacrylate and reported in environmental assessments by Environment and Climate Change Canada. Waste management and recycling practices recommended by manufacturers such as 3M and BASF emphasize polymerization, stabilization, and wastewater treatment strategies used in industrial facilities operated by conglomerates including Shell and ExxonMobil to mitigate monomer release.

Category:Monomers