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><sub>w</sub>/<i>M</i><sub>n</sub> = 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
