Living Anionic Polymerization in Continuous Flow: Facilitated Synthesis of High-Molecular Weight Poly(2-vinylpyridine) and Polystyrene

Abstract

We describe the living anionic polymerization of 2-vinylpyridine (2VP) and styrene (S) in continuous flow, comparing two micromixing devices with different mixing principles. 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 four-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 four-way jet mixing device led to lower polydispersity than the laminar mixing device. All polymers were characterized by 1 H NMR spectroscopy and size exclusion chromatography (SEC).

Continuous flow synthesis of poly(methyl methacrylate) via a light‐mediated controlled radical polymerization

“…Chains growing at different rates depending on their location in the reactor could give rise to broader dispersities for the resulting polymer. Continuous flow microreactors are particularly attractive for addressing the drawbacks of light‐mediated reactions as shown in Scheme (a).…”

Anionic Polymerization Using Flow Microreactors

“…When performed in batch macro reactors, the polymerization needs inorganic salts such as lithium chloride to control the reaction. However, the reaction can be quenched in a timely manner by precise residence time control so that it prevents carbanionic living polymer ends from reacting with electron-poor pyridine ring [94,95].…”

Ring‐Opening Polymerization of Propylene Oxide by Double Metal Complex in Micro‐Reactor

“…Many highly exothermic and extremely fast reactions involving small molecules, such as nitrification reaction,18 oxidation reaction,19 diazotization reaction,20 and fluorination reaction,15 were conducted in continuous micro‐reactor (C‐MR) to ensure safety or improve selectivity. Some polymerizations, including free radical polymerization,21–23 cationic polymerization,24–26 anionic polymerization27–29 and poly‐condensation30 have been conducted in C‐MR also. As a result, polymers with narrow particle size distribution21 or narrow MWD,22,23,25–30 or increased yield28,30 were obtained benefiting from fast mixing (reducing concentration gradients) and fast heat transfer (reducing hot spots).…”

“…Some polymerizations, including free radical polymerization,21–23 cationic polymerization,24–26 anionic polymerization27–29 and poly‐condensation30 have been conducted in C‐MR also. As a result, polymers with narrow particle size distribution21 or narrow MWD,22,23,25–30 or increased yield28,30 were obtained benefiting from fast mixing (reducing concentration gradients) and fast heat transfer (reducing hot spots).…”