Building blocks for polymer synthesis by enzymatic catalysis

Abstract: The search for alternatives to oil-based monomers has sparked interest for scientists to focus on the use of renewable resources for energy production, for the synthesis of polymeric materials and in other areas. With the use of renewable resources, scientists face new challenges to first isolate interesting molecules and then to process them.Enzymes are nature’s own powerful catalysts and display a variety of activities. They regulate important functions in life. They can also be used for chemical synthesis due to their efficiency, selectivity and mild reaction conditions. The selectivity of the enzyme allows specific reactions enabling the design of building blocks for polymers.In the work presented here, a lipase (Candida antarctica lipase B (CalB)) was used to produce building blocks for polymers. An efficient route was developed to selectively process epoxy-functional fatty acids into resins with a variety of functional groups (maleimide, oxetane, thiol, methacrylate). These oligoester structures, based on epoxy fatty acids from birch bark and vegetable oils, could be selectively cured to form thermosets with tailored properties.The specificity of an esterase with acyl transfer activity from Mycobacterium smegmatis (MsAcT) was altered by rational design. The produced variants increased the substrate scope and were then used to synthesize amides in water, where the wild type showed no conversion. A synthetic procedure was developed to form mixed dicarboxylic esters by selectively reacting only one side of divinyl adipate in order to introduce additional functional groups.