Efficient preparation of cyclic polymers via pre-stacking of photo-cycloaddition capable end groups and a continuous-flow technique

Abstract

Cyclic polymers have recently attracted more and more attention due to their unique structures and performance, but their synthesis still presents great challenges. The commonly used ring-closure strategy to synthesize...

Regulation of Two-Dimensional Platelet Micelles by Dynamic Changing of Polymer Topological Architectures upon Light Irradiation

“…Taking (PCL 10 -SPy) 2 as an example, we used ultraviolet–visible (UV–vis) and fluorescence spectroscopies in THF solution (0.25 mg/mL) under 430 nm visible light irradiation to characterize the dynamic cyclic reaction (Figure ). From UV–vis spectra, the absorption band at 382 nm decreased upon 430 nm visible light irradiation and remained stable after 100 min, which indicated the implementation of the [2 + 2] photocycloaddition reaction. Meanwhile, the absorption at 338 and 350 nm wavelengths, as characteristic peak of alkyl pyrene, gradually increased upon 430 nm visible light irradiation (Figure A).…”

Designed to Degrade: Tailoring Polyesters for Circularity

“…This allows for a straightforward way of designing photoreactive materials for different applications. How to favor the intramolecular reactions during photodimerization has been further investigated in several studies since then. − As an example, PCL was end-functionalized with anthracene units to synthesize reversibly cyclic PCL (cPCL) of high molecular weights and variable ring sizes . By varying the concentration of end-functionalized PCL in solution during irradiation, rings of different sizes could be synthesized.…”

Accessing Cyclobutane Polymers: Overcoming Synthetic Challenges via Efficient Continuous Flow [2 + 2] Photopolymerization

“…Additionally, in contrast to traditional batch photoreactors which are often plagued by scalability issues, continuous flow is a viable alternative for efficient, large-scale photopolymerizations. Continuous flow strategies have been previously employed for [2 + 2] photocycloadditions of small molecules ,, and as postpolymerization ring-closing mechanisms of polymer reactive end-groups; however, this report describes the first continuous flow [2 + 2] polymerization. We constructed an in-house flow photoreactor comprised of 1/8-in.…”