(35c) Microfluidic-Assisted Nitroxide-Mediated Copolymerizations: Influence of the Micromixer Geometry

Microreaction technology is becoming a very important topic of today's polymer reaction engineering. Due to their good thermal and mass transport properties, as compared to conventional labscale batch reactors, microfluidic devices can be used to carry out exothermic and diffusion-controlled reactions such as polymerizations. Recently, we showed the enhancement of the control over the continuous Nitroxide-Mediated Block Copolymerization (NMBC) reactions, carried out in two microtube reactors connected in series with a micromixer in between. In all experiments, the microsystem gives the smallest polydispersity indices in contrast to the batch process. In this work, the influence of the micromixer's geometry on the molecular weight distribution of the copolymers is investigated on different polymer systems. We highlight the fact that the control of the polymerization can be improved just by using very narrow microchannels inside the micromixer, i.e. by decreasing the film thicknesses of the polymer solutions.