Synthesis of Hyperbranched Polyglycerol in a Continuous Flow Microreactor

Abstract

Abstract Hyperbranched polymers have been synthesized in a microreactor for the first time, employing the known ring‐opening multibranching polymerization of glycidol. Microreactors are well‐known to be beneficial for highly exothermic reactions because of their capability to enhance mass and heat transfer due to short diffusion pathways and large interfacial areas per volume. The characteristics of the microstructured reaction system were utilized to engineer a continuous flow process for the preparation of well‐defined hyperbranched polyglycerols with molecular weights up to 1,000 g/mol. Increased flow rates, as well as the use of highly polar solvents, led to the partial formation of very narrowly distributed ( M w / M n = 1.05–1.15) high molecular weight fractions ( M n up to 150,000 g/mol). NMR‐ and MALDI‐ToF spectra confirmed incorporation of the multifunctional initiator core into the hyperbranched polymer structure.