Prof. Dr. Axel Müller

We describe the living anionic polymerization of 2-vinyl pyridine (2VP) and styrene (S) in continuous flow, comparing two micromixing devices with different mixing principle. The use of a continuous flow setup reduces the experimental effort for living anionic polymerizations significantly, compared to a conventional batch system. By adjusting the ratio of the flow rates of the monomer and initiator solutions a variety of different molecular weights can be rapidly synthesized within several minutes, using one setup. Additionally, a comparison of the influence of the two different mixing devices - an interdigital micromixer (SIMM-V2) leading to laminar mixing and a tangential 4-way jet mixing device leading to a turbulent mixing pattern - has been achieved. Both setups allow living anionic polymerization in polar solvents at room temperature with full monomer conversion within seconds and yield polymers with narrowly distributed molecular weights. A maximum M_n of approximately 149,000 g mol^-1 (PS-9, PDI = 1.04) for PS and 96,000 g mol^-1 for P2VP (P2VP-15, PDI = 1.05) was obtained. Clearly, the turbulent 4-way jet mixing device led to lower polydispersity than the laminar mixing device. All polymers were characterized by ¹H NMR spectroscopy and size exclusion chromatography (SEC).