This paper provides a third update to the review of reversible deactivation radical polymerization (RDRP) achieved with thiocarbonylthio compounds (ZC(=S)SR) by a mechanism of reversible addition-fragmentation chain transfer (RAFT) that was published in June 2005 (Aust. J. Chem. 2005, 58, 379). The first update was published in November 2006 (Aust. J. Chem. 2006, 59, 669) and the second in December 2009 (Aust. J. Chem. 2009, 62, 1402). This review cites over 700 publications that appeared during the period mid 2009 to early 2012 covering various aspects of RAFT polymerization which include reagent synthesis and properties, kinetics and mechanism of polymerization, novel polymer syntheses, and a diverse range of applications. This period has witnessed further significant developments, particularly in the areas of novel RAFT agents, techniques for end-group transformation, the production of micro/nanoparticles and modified surfaces, and biopolymer conjugates both for therapeutic and diagnostic applications.

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Living Radical Polymerization by the RAFT Process - A Second Update

Radical addition-fragmentation chemistry in polymer synthesis

Continuous-flow photochemistry in microreactors receives a lot of attention from researchers in academia and industry as this technology provides reduced reaction times, higher selectivities, straightforward scalability, and the possibility to safely use hazardous intermediates and gaseous reactants. In this review, an up-to-date overview is given of photochemical transformations in continuous-flow reactors, including applications in organic synthesis, material science, and water treatment. In addition, the advantages of continuous-flow photochemistry are pointed out and a thorough comparison with batch processing is presented.

Applications of Continuous-Flow Photochemistry in Organic Synthesis, Material Science, and Water Treatment

A living radical polymerization (LRP) is a free radical polymerization that aims at displaying living character, (i.e., does not terminate or transfer and is able to continue polymerization once the initial feed is exhausted by addition of more monomer). However, termination reactions are inherent to a radical process, and modern LRP techniques seek to minimize such reactions, therefore providing control over the molecular weight and the molecular weight distribution of a polymeric material. In addition, the better LRP techniques incorporate many of the desirable features of traditional free radical polymerization, such as compatibility with a wide range of monomers, tolerance of many functionalities, and facile reaction conditions. The control of molecular weight and molecular weight distribution has enabled access to complex architectures and site specific functionality that were previously impossible to achieve via traditional free radical polymerizations. These LRPs are classified in three different subgroups: (1) stable free-radical polymerization such as nitroxide mediated polymerization (NMP),1,2 (2) degenerative transfer polymerization, such as iodine transfer polymerization (ITP and RITP),3,4 single electron transfer-degenerative transfer living radical polymerization(SET-DTLRP),5,6reversibleaddition-fragmentation chain transfer (RAFT),7,8 and macromolecular design via the interchange of xanthates (MADIX)9,10 polymerization, and (3) metal mediated catalyzed polymerization, such as atom transfer radical polymerization (ATRP),11-14 single electron transfer-living radical polymerization (SET-LRP),15 and organotellurium mediated living radical polymrization16-19 Among the existing LRP techniques, RAFT and MADIX are probably the most versatile processes, as they are tolerant * E-mail: T.P.D., T.Davis@UNSW.edu.au; S.P., S.Perrier@ chem.usyd.edu.au. † Centre for Advanced Macromolecular Design (CAMD), School of Chemical Sciences & Engineering, UNSW. ‡ Centre for Advanced Macromolecular Design (CAMD), School of Biotechnology & Biomolecular Sciences, UNSW. § The University of Sydney. Chem. Rev. 2009, 109, 5402–5436 5402

Bioapplications of RAFT polymerization.

Photochemical reactions, particularly those involving photoinduced electron transfer processes, establish a substantial contribution to the modern synthetic chemistry, and the polymer community has been increasingly interested in exploiting and developing novel photochemical strategies. These reactions are efficiently utilized in almost every aspect of macromolecular architecture synthesis, involving initiation, control of the reaction kinetics and molecular structures, functionalization, and decoration, etc. Merging with polymerization techniques, photochemistry has opened up new intriguing and powerful avenues for macromolecular synthesis. Construction of various polymers with incredibly complex structures and specific control over the chain topology, as well as providing the opportunity to manipulate the reaction course through spatiotemporal control, are one of the unique abilities of such photochemical reactions. This review paper provides a comprehensive account of the fundamentals and applications ...

Photoinduced Electron Transfer Reactions for Macromolecular Syntheses

The past 5 years have seen a significant increase in the understanding of the fate of so-called mid-chain radicals (MCR), which are formed during the free radical polymerization of monomers that form highly reactive propagating radicals and contain an easily abstractable hydrogen atom. Among these monomers, acrylates are, beside ethylene, among the most prominent. Typically, a secondary propagating acrylate-type macroradical (SPR) can easily transfer its radical functionality via a six-membered transition state to a position within the polymer chain (in a so-called backbiting reaction), creating a tertiary MCR. Alternatively, the radical function can be transferred intramolecularly to any position within the chain (also forming an MCR) or intermolecularly to another polymer strand. This article aims at providing a comprehensive overview of the up-to-date knowledge about the rates at which MCRs are formed, their secondary reactions as well as the consequences of their occurrence under variable reaction conditions. We explore the latest aspects of their detection (via electron spin resonance spectroscopy) as well as the characterization of the polymer structures to which they lead (via high resolution mass spectrometry). The presence of MCRs leads to the formation of branched polymers and the partial formation of polymer networks. They also limit the measurement of kinetic parameters (such as the SPR propagation rate coefficient) with conventional methods. However, their occurrence can also be used as a synthetic handle, for example, the high-temperature preparation of macromonomers. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7585–7605, 2008

https://onlinelibrary.wiley.com/doi/pdf/10.1002/pola.23071

The role of mid-chain radicals in acrylate free radical polymerization: Branching and scission

The past 5 years have seen a significant increase in the understanding of the fate of so-called mid-chain radicals (MCR), which are formed during the free radical polymerization of monomers that form highly reactive propagating radicals and contain an easily abstractable hydrogen atom. Among these monomers, acrylates are, beside ethylene, among the most promi-nent. Typically, a secondary propagating acrylate-type macro-radical (SPR) can easily transfer its radical functionality via a six-membered transition state to a position within the polymer chain (in a so-called backbiting reaction), creating a tertiary MCR. Alternatively, the radical function can be transferred intramolecularly to any position within the chain (also forming an MCR) or intermolecularly to another polymer strand. This article aims at providing a comprehensive overview of the up-to-date knowledge about the rates at which MCRs are formed, their secondary reactions as well as the consequences of their occurrence under variable reaction conditions. We explore the latest aspects of their detection (via electron spin resonance spectroscopy) as well as the characterization of the polymer structures to which they lead (via high resolution mass spectrometry). The presence of MCRs leads to the formation of branched polymers and the partial formation of polymer networks. They also limit the measurement of kinetic parameters (such as the SPR propagation rate coefficient) with conventional methods. However, their occurrence can also be used as a synthetic handle, for example, the high-temperature preparation of macromonomers. © 2008 Wiley Periodicals, Inc.

Sequence-definition from controlled polymerization: the next generation of materials

Tailoring Polymer Dispersity by RAFT Polymerization: A Versatile Approach

A novel continuous flow system for automated high-throughput screening, autonomous optimization, and enhanced process control of polymerizations was developed. The computer-controlled platform comprises a flow reactor coupled to size exclusion chromatography (SEC). Molecular weight distributions are measured online and used by a machine-learning algorithm to self-optimize reactions towards a programmed molecular weight by dynamically varying reaction parameters (i.e. residence time, monomer concentration, and control agent/initiator concentration). The autonomous platform allows targeting of molecular weights in a reproducible manner with unprecedented accuracy (<2.5 % deviation from pre-selected goal) for both thermal and light-induced reactions. For the first time, polymers with predefined molecular weights can be custom made under optimal reaction conditions in an automated, high-throughput flow synthesis approach with outstanding reproducibility.

Tanja Junkers

Papers

The role of mid-chain radicals in acrylate free radical polymerization: Branching and scission

The role of mid-chain radicals in acrylate free radical polymerization: Branching and scission

Sequence-definition from controlled polymerization: the next generation of materials

Tailoring Polymer Dispersity by RAFT Polymerization: A Versatile Approach

Precise Polymer Synthesis by Autonomous Self-Optimizing Flow Reactors.