Acrylates

Acrylates are esters derived from acrylic acid and various alcohols. They are commonly encountered as monomers that undergo radical polymerization to form polyacrylates and as polymers themselves used in coatings, adhesives, and plastics. The term also covers methacrylate esters, which relate to methacrylic acid and are widespread in dental and biomedical polymers.

Chemically, acrylates have the general structure CH2=CH-COOR, where R is an alkyl group. Methacrylates have CH2=C(CH3)-COOR. The vinyl double bond allows addition polymerization. Polymerization is typically initiated by radical initiators, heat, or ultraviolet light, often with inhibitors and chain transfer agents to control rate and crosslinking.

Common acrylate monomers include methyl acrylate, ethyl acrylate, and butyl acrylate; common methacrylates include methyl methacrylate (MMA) and hydroxyethyl methacrylate (HEMA). Polyacrylates exhibit a range of properties from rigid to flexible and can be formulated with crosslinkers to produce thermosetting resins or thermoplastics.

Applications are broad: acrylate polymers are used in paints and coatings, adhesives and sealants, textile finishes, ophthalmic lenses, dental resins, hydrogels for biomedical uses, and UV-curable coatings. Their transparency and weather resistance are valued, though some acrylates can be skin sensitizers.

Safety: monomers can be irritants and sensitizers, with methacrylates notably associated with contact dermatitis in sensitive individuals. Proper handling, ventilation, and curing are important to minimize exposure.