Feasibility Study on Continuous Flow Controlled/Living Anionic Polymerization Processes

A practical microchemical reaction system for keeping process flow at defined conditions, which is one of the key issues of industrial production, was developed. Controlled/living anionic polymerization was chosen as a test reaction because the molecular weight and molecular weight distribution of polymer products are quite sensitive to the relative flow rate of an initiator solution and that of a monomer solution. The polymerization of styrene in THF/hexane was carried out using a flow microreactor system consisting of two T-shaped micromixers and two microtube reactors using Smoothflow pumps at 0 °C. Poly­(styrene) with higher molecular weight such as Mn > 10000 could be synthesized using <i>s</i>-BuLi (Mn = 14 000, <i>M</i>_w/<i>M</i>_n = 1.11). <i>n</i>-BuLi could also be used as an initiator. The continuous operation was performed for 3 h without any problems to obtain ca. 1 kg of the polymer, indicating the feasibility of continuous flow processes for controlled/living anionic polymerization on a relatively large scale