Anionic polymerization driven by flow microchemistry

Abstract

This focus review describes advancements in anionic polymerization achieved using flow microreactors. Anionic polymerization using traditional flask chemistry often requires extremely low temperatures and complex setups; thus, it is unsuitable for large-scale production. Flow microreactors, with features such as precise temperature control, rapid mixing, and precise time control, can overcome these limitations. Using these microreactors, otherwise impossible polymer synthesis reactions can occur, and a controlled molecular weight distribution and high reaction selectivity is attained. Due to the ability to perform reactions at high temperatures without excessive cooling, this method is environmentally friendly and cost-effective. Additionally, precise time control allows the use of highly unstable polymer chain ends and functionalized alkyllithiums for further reactions, facilitating the synthesis of heterotelechelic polymers. Similar to those in laboratory-scale experiments, the continuous operation of the flow microreactors can be used to scale up the reaction under conditions, demonstrating their potential for industrial applications. This focus review highlights the significant contributions of flow microreactors to polymer production and facilitates future advancements in high-speed, environmentally benign polymer synthesis. Our recent studies on the anionic polymerization achieved using flow microreactors are reviewed. Using flow microreactors, with features such as precise temperature control, rapid mixing, and precise time control, otherwise impossible polymer synthesis reactions can occur. Some typical examples synthesizing polymers with reactive functional groups and heterotelechelic polymers are described. This review also highlights the in-line analyses of the polymer living end, helping a deeper insights of the reaction and its conditions. The continuous operation of the flow microreactors demonstrated their potential for industrial applications.