Lipase-catalyzed syntheses of telechelic polyesters

Telechelic polyesters have successfully been synthesized with lipasecatalyzed polymerization. The produced telechelics had a high degree of difunctionalization, high purity (requiring little or no workup) and controlled degree of polymerization. The syntheses were performed in one-pot one-step reaction systems. Two different types of lipase-catalyzed polymerizations were applied – ring-opening polymerization and polycondensation. In ring-opening polymerization telechelics were produced by a combination of initiation, α-functionalization, and linking through termination, -functionalization. In polycondensation different types of end-cappers were used to synthesize telechelics. Several exampels of functional groups were used for end-functionalization epoxide, methacrylate and tetraallyls. Enzyme kinetic schemes describing the different functionalization methods of polyesters are presented and discussed. Stoichiometry and different reaction conditions have been studied to understand the effects these functions have on the final structure of the synthesized telechelics. Polyesters are classified as biodegradable, and can also be synthesized from materials that can be extracted or fermented from renewable sources like plants. Lipasecatalysts have several beneficial attributes, like high selectivity, they are renewable and biodegradable, are non-toxic and metal-free and can operate under mild reaction conditions. The focus of this thesis has been on lipase-catalyzed syntheses and characterization of the produced telechelics, in addition some materials have been produced. Some uses of telechelics are surface modification, materials for block co-polymers, functional films and biomedical applications.