Photocontrolled RAFT polymerization: past, present, and future

Abstract

This review summarizes the development, progress, applications, and future challenges of photocontrolled reversible addition–fragmentation chain transfer (RAFT) polymerization, which has attracted considerable attention in the past several years.

Light-Driven Organocatalyzed Controlled Radical Polymerization from Sulfonyl Chloride Initiators Promoted by Bis(thiocarbonyl) Disulfides

“…Photopolymerizations have been broadly adopted in both academia and industry for several decades, thanks to their convenience, simplicity, low cost, and so forth. − Photo-controlled radical polymerization (photo-CRP) variants of atom transfer radical polymerization (ATRP), − reversible addition fragmentation chain transfer (RAFT) polymerization, − metal-mediated CRPs, − and others , have not only allowed polymer synthesis with pre-defined molecular weights (MWs) and chemical structures, as well as good chain-end fidelity, but also created opportunities to achieve temporal control over chain-growth processes. Recently, inspired by photoredox catalysis, the light-enabled manipulation of single electron transfer (SET) has been merged with CRPs, ,− bringing a variety of attractive characteristics to polymer fabrications .…”

Continuous-Flow PET-RAFT Polymerization in a Packed-Bed Reactor with Porphyrin-Immobilized Silica Particles

“…Controlled polymerization techniques, such as reversible-deactivation radical polymerization (RDRP), provide the production of synthetic polymers with well-defined structures (e.g., desired molecular weight, narrow molecular weight distribution, and multiple block segments). , These characteristics enable the production of valuable polymer products, including coating agents, emulsion particles, and drug carriers . Photoinduced electron/energy transfer-reversible addition–fragmentation chain transfer (PET-RAFT) polymerization is a beneficial method for producing such well-controlled synthetic polymers through a green process utilizing light source energy. − To harness low-energy visible light as the driving force for PET-RAFT polymerization, various examples of photocatalysts have been reported . Tetraphenylporphyrin (TPP) is one of the porphyrin derivatives and exhibits strong absorption in the visible-light range.…”

Photocatalytic ATRP Depolymerization: Temporal Control at Low ppm of Catalyst Concentration

“…Reversible deactivation radical polymerization (RDRP) has enabled precise control over the molecular weight, molar mass distributions, sequence, architecture and end-group fidelity. , In atom transfer radical polymerization (ATRP) and reversible addition–fragmentation chain-transfer (RAFT) polymerization, arguably the two most dominant controlled radical methodologies, this control is achieved by regulating the activation/deactivation equilibrium between active and dormant species. − In recent years, significant efforts have been dedicated toward controlling the activation/deactivation equilibrium via external stimuli. − Among them light has attracted significant attention, as it inherently possesses a number of unique properties and characteristics, such as high abundance, wide availability, and low cost, while it provides further possibilities for temporal and spatial control leading to its further implementation in 3D printing. − In addition, photomediated polymerizations present significant advantages over traditional thermal approaches including faster reaction times, higher monomer conversions, and enhanced control over the molar mass distributions. − …”