(62b) Amino Acid Polymerization in Micro-Reactor

Microreaction systems involve microreaction apparatus that enables high controllability of chemical reactions. Such controllability results from efficient heat transfer, mass transport, and/or larger surface/interface area. Recent studies have shown the potential benefits of applying the various chemical reactions to microfluidic reactors. Several polymerization reactions have been performed using microreaction systems. Reactions using micromixing devices gave better results than that of batchwise reactions. This is because micromixer enables rapid mixing and therefore yields excellent controllability of rapid reactions. Our group has been interested in chemical reactions and analysis methods utilizing hydrodynamic behaviors generated characteristically in microfluids, including laminar flow, secondary flow, and shearing force. We have shown that polymer chain can be expanded and oriented in microfluidic system using DNA as a model. Such behaviour demonstrates the utility of microreactor as novel reaction apparatus for polymers. Taking into account the properties of microfluidic systems, we have decided to apply microreaction technology in biopolymer synthesis. In the present study, we performed polymerization reactions of amino acid N-carboxyanhydride (NCA) as a model. It was found that the microreactor produced polymers with more homogeneous molecular weight distribution as compared with polymers obtained by batchwise system. Also, the molecular mass of the polymer produced using the microreactor was simply governed by the flow (pumping) rate. These results indicated that the microreactor could be a model for synthesis of biopolymer with highly controllable average molecular weight and molecular weight distribution. Detailed analyses such as effects of microchannel structure and sharing force on average molecular weight and molecular weight distribution will be discussed.