Enzymatic esterification of polymer acid groups

Researchers at Polytechnic University in Brooklyn, NY, devised an enzymatic process to esterify a broad variety of polymers with attached acid groups, with a number of different alcohols. In applying the technology to esterifying polyacrylic acid with ethylene glycol, the group heated one part by weight of the polymer with three parts of the glycol to 85 degrees C, with a commercial lipase enzyme from Candida antarctica B for 24 hours to 36 hours. Applying a vacuum at intervals removed the water formed by the reaction. The product was a copolymer containing acrylic acid and 2-hydroxyethyl acrylate.