Photo-induced copper-mediated radical polymerization of methyl acrylate (MA) is carried out in DMSO at 15 C in a tubular photo-flow reactor as well as in a glass-chip based microreactor. Polymerization reactions proceed rapidly to approximately 90% monomer conversion within 20 minutes of reactor residence time.Control of reactions is high as evidenced by ideal polymerization kinetics, low dispersities of the obtained polymers (in the range of 1.1) and linear evolution of number average molecular weights during polymerization reactions. Poly(MA) with average molecular weights between a few hundred and $5000 g mol À1 was obtained under retention of pristine end group fidelity. Besides homopolymers, block copolymers can also be successfully synthesized and poly(methyl acrylate)-b-poly(butyl acrylate) block copolymers with a similar low dispersity are obtained. Reactions proceed under homogeneous reaction conditions. This feature allows the reaction to be carried out in milli-and also in microflow devices. In both cases, equally good control is achieved with only minimal adaptation of the reaction protocol, underpinning the simplicity and fast adaptability of the protocol to different flow reactors.

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Via the combination of nitrone-mediated radical coupling and cobalt-mediated radical polymerization, mid-chain functionalized polymers are obtained that can be assembled into H-shaped polymers.

The alkene–enone [2 + 2] photocycloaddition reaction between polymer-bound maleimide and functional alkenes has been tested in a UV-flow reactor, demonstrating a very high efficiency of the reaction. As a test reaction, polymer end group modifications were carried out on maleimide-functional poly(butyl acrylate). The polymer was prepared by atom transfer radical polymerization (ATRP) using a N-hydroxysuccinimide-functionalized initiator, followed by exchange reaction of the activated ester with a maleimide amine linker. Good control over the polymerization and successful exchange of the end group under mild reaction conditions was confirmed by electrospray ionization mass spectrometry (ESI-MS). The terminal maleimide group was then reacted quantitatively with alkenes in a custom-made tubular UV-flow reactor within a minute reaction time. Compared to reaction times in batch of several hours to days, the reaction proceeds to full conversion within 1 min under flow conditions. This significant acceleration of the reaction was achieved by employing a photosensitizer in combination with the flow reactor technique. Via the cycloaddition a variety of functional groups can be introduced to the polymer chain ranging from multifunctional allyl compounds to hydroxyl-functional alkenes, demonstrating the general versatility and high potential of the approach for polymer modification reactions.

Molecularly imprinted polymers (MIPs) in the micron and submicron scale based on the bifunctional cross-linker N,O-bismethacryloyl­ethanol­amine (NOBE) have been synthesized using bulk and miniemulsion polymerization, respectively. MIPs with distinct selectivity for the template testosterone were obtained. Colloidal MIP particles made using the miniemulsion technique have significant advantages compared to bulk MIP counterparts owing to their small size, homogeneity, and increased surface, as is demonstrated by optical batch rebinding studies using a nonimprinted polymer (NIP) as a negative control. Affinity and selectivity studies were also performed with the miniemulsion colloidal MIPs. These MIPs display largely increased imprint factors (6.8 vs 2.2) when compared to their bulk MIP counterparts. Further, selectivity studies by using analogue steroids show that colloidal MIPs also display a higher selectivity. In summary, miniemulsion MIPs show much better performance with respect to molecular recognition in aqueous solution, while providing at the same time the possibility for a water-based MIP synthesis.