(130b) Well-Defined Hyperbranched and Linear Polymers by Anionic Polymerization in Continuous Flow

Microreactor-based processes offer intriguing potential with respect to polymerizations (particularly ring-opening polymerizations), since they usually proceed strongly exothermic and are diffusion-limited due to their fast kinetics. Here we describe the development of an efficient continuous flow process for the first example of a hyperbranching polymerization in a microstructured reactor. Our approach permits the preparation of well-defined hyperbranched polyglycerol (a highly versatile and biocompatible polymer) with Mn up to 1,000 g/mol under significant reduction of the reaction time compared to the conventional batch procedure. Analysis by NMR spectroscopy and MALDI ToF MS showed complete incorporation of the initiator core moiety into the hyperbranched structure.

An analogous microreactor set-up was employed for the preparation of very narrowly dispersed (Mw/Mn < 1.1) linear polymers by living anionic polymerization of vinyl monomers in continuous flow, applying reaction conditions that cannot be realized in a conventional set-up due to the highly exothermic nature of the polymerization reaction. Monomer conversion was complete after several minutes instead of hours in the traditional approach.