Lipase-catalyzed syntheses of linear and hyperbranched polyesters using compressed fluids as solvent media

Enzyme-mediated syntheses of polyester structures are described using green compressed fluids as solvent media, thus avoiding the use of toxic volatile organic compounds or metal catalyst. Supercritical carbon dioxide is presented as a adequate medium for enzymatic synthesis of relatively high molecular weight poly(delta-valerolactone). Alternatively, liquid 1,1,1,2-tetrafluoroethane (R-134a) is a green, non-toxic, relatively polar and hydrophobic solvent, which enhances the solubility of many substrates of interest along with sustained lipase activity for successful syntheses of linear and hyperbranched polyesters. Moreover, liquid R-134a functions under mild reaction conditions (25 bar and 65 degrees C). (C) 2010 Elsevier B.V. All rights reserved.