polyacrylates

Polyacrylates are polymers derived from acrylate monomers, a diverse family that includes poly(alkyl acrylates) such as poly(methyl acrylate), poly(ethyl acrylate), poly(n-butyl acrylate), and poly(2-ethylhexyl acrylate), as well as polymers of acrylic acid and its salts. The repeating unit in esters is -CH2-CH(COO-R)-, while polyacrylic acid consists of -CH2-CH(COOH)- units. They are produced predominantly by free radical polymerization, using bulk, solution, suspension, or emulsion methods. Emulsion polymerization yields latexes that are especially common in coatings and adhesives; crosslinking agents can produce thermoset networks.

The properties of polyacrylates are largely governed by the ester group and by crosslinking. Long alkyl side chains confer flexibility and low glass-transition temperatures, while polar or bulky groups raise Tg and can improve film-forming and adhesion. Carboxyl groups in polyacrylic acid or ionized polyacrylates impart water solubility or water swellability; crosslinking or salt formation often increases water resistance. Crosslinked polyacrylates form hydrogels or thickened gels used in products such as carbomers.

Applications span paints, coatings, and adhesives; cosmetics and personal care products use polyacrylates as thickeners and stabilizers; in the medical and dental fields, certain polyacrylates serve as components of hydrogels and denture materials. Sodium polyacrylate and similar polymers act as superabsorbent materials in diapers and as thickening agents in various formulations. Safety considerations include irritation potential of monomers and handling requirements during polymerization.