The enzymatic synthesis of polyesters from Low molecular weight polyesters that can be syntheactivated diesters and diols has been investigated. Difsized via lipase catalyzed polytransesterification, if ferences between enzymatic synthesis and traditional completely terminated by hydroxyl groups, can be chemical condensation processes are discussed. The used as soft block elements in the further synthesis disappearance of monomers during the initial phase of of polyurethane elastomers (Bayer, 1950). The curreaction indicates that enzyme has a higher specificity for transesterification of ester-terminated oligomers.
rent commercial prepolymer synthesis involves bulk/
During the intermediate phase, enzymatic polymerizasolution polymerization of dicarboxylic acids with tion involves a competition between diol and enzymediols at high temperatures (Kopnick et al., 1992). bound water for the nucleophilic attack of the acyl Limitations of the current process include ether forenzyme intermediate. Competition between enzymatic transesterification and hydrolysis at different stages of mation (due to dehydration of diol), and lactone polymerization in nonaqueous media is responsible for ring formation. Enzymes offer potential advantages termination of polyesters with acid end-groups and also as oligoester synthesis catalysts since they are spefor limiting the polymer molecular weight. The resulting cific and also operate under mild reaction condioligoester consists of chains that are either terminated tions. Indeed, the selective nature of biological catawith UOH groups and/or UCOOH groups. We have used Matrix Assisted Laser Desorption/Ionization Ϫ Time of lysts has enabled the synthesis of optically active Flight Mass spectroscopy (MALDI-TOF) along with colorpolyesters at ambient conditions (Wallace and Morimetric titration techniques to determine the acidity of row, 1989a).
enzyme-synthesized polyesters. This paper addresses
There have been reports on increasing the degree of how the enzymatic polymerization proceeds, and compares our results to the growing literature in this field.