Polymer synthesis in continuous flow reactors

A variety of polymerizations has long been performed in continuous flow reactors on an industrial scale; comparatively, on smaller scales, continuous polymerization methods have only gained significant attention in recent years. Yet, within the last decade, the field has moved from the rare occurrence of flow reactors to their abundant use today. A wide variety of polymer reactions have been performed in a continuous fashion on small and intermediate scales. The advantages of applying flow chemistry principles for polymer reactions include increased reproducibility and synthetic precision, significant increases in reaction performances for photochemical reactions, the ability to couple reactors to create complex materials in a single reactor pass, as well as the unique combination of online monitoring and machine learning. In this review we give a comprehensive overview of polymer reactions being carried out in continuous flow reactors to date. The development of the field is discussed, concluding with the most recent examples on automated polymer synthesis, reactor telescoping and nanoparticle synthesis. Finally, the design of flow reactors is discussed to help newcomers contribute to the current and future developments in the field.