Continuous Flow Photoinduced Reversible Deactivation Radical Polymerization

Abstract

Photoinduced reversible deactivation radical polymerization (RDRP) is a versatile and robust method to yield well‐defined polymers under mild conditions with additional advantages of spatial and temporal control. The process and scalability of photoinduced RDRP in the batch mode, however, are limited by the inherent light gradient effect according to the Beer–Lambert law. The continuous flow technique, as an alternative methodology, provides a solution to improve the irradiation efficiency and scale up the polymerization. This Minireview highlights recent progress in continuous flow photoinduced RDRP since 2016. Reversible termination RDRP, degenerative transfer RDRP and others are reviewed in consecutive order. An outlook for continuous flow photoinduced RDRP is also discussed.

Photoiniferter surface grafting of poly(methyl acrylate) using xanthates

“…This may indicate progressive degradation of the xanthate functionality upon UV radiation. However, the grafting of PMA was confirmed by the detection of CH 3 O − (the pending methyl ester) and C 4 H 5 O 2 − , which were clearly detectable in ToF-SIMS. As a control experiment, the exact same procedure for the grafting of PMA was repeated on blank silicon substrates to rule out physisorption of methyl acrylate.…”

“…On planar substrates, combining the advantages of controlled polymerizations with the advantages of photoinitiation allows for engineering of complex structures and patterns with the addition of spatial and temporal control over the reaction. [2][3][4] Two of the most studied, and best known photoRDRP strategies are photoinitiated atom transfer radical polymerization (photoATRP) and photoreversible addition-fragmentation degenerative chain-transfer (photoRAFT). 2,[5][6][7] PhotoATRP uses a catalyst to reduce the activator upon photoexcitation, yielding a radical accessible for propagation.…”

Advances in the Synthesis of π‐Conjugated Polymers by Photopolymerization

“…Producing soluble polymers with high molecular weight remains a challenge for both oxidative and reductive photopolymerization. The inherent high optical density of CPs adds a technical challenge to using light for their polymerization, likely necessitating the use of flow chemistry [55–57] . Flow chemistry has been shown to offer greater control of photopolymerizations by offering shorter path lengths and more homogenous irradiation compared to batch reactions [58] .…”

Ten Chemical Innovations That Will Change Our World: IUPAC identifies emerging technologies in Chemistry with potential to make our planet more sustainable

“…There are now many methods to control RDRP processes using only light, even without the need of using metals [18]. In recent years, chemists have also developed RDRP methods that work in flow systems, which will allow them to move towards greener synthesis of polymers and plastics [19].…”