Controlled radical polymerization methods

Betts, D. E. Johnson, T. LeRoux, D. DeSimone, J. M. Controlled Radical Polymerization Methods for the Synthesis of Nonionic Surfactants for C02. 

Among the several controlled radical polymerization methods, atom transfer radical polymerization (ATRP) is one of the most attractive techniques. The proposed mechanism of ATRP is shown in Fig. 10. The radicals were formed by atom transfer of a halogen from a dormant species to a metal. This transfer is possible due to the capacity of the metal to change its oxidation state. This... 

Despite the fast development and versatility of controlled radical polymerization methods for a variety of vinyl monomers, there is still a need for cationic polymerization methods for certain important monomer classes, in... 

The advent of controlled radical polymerization methods, such as ATRP, RAFT, and NMP, has allowed for a wide variety of new block and graft polymers to be prepared due to the chemical variety of monomers which can be polymerized by these methods (Matyjaszewski and Tsarevsky, 2009 Matyjaszewski and Braunecker, 2007). Block copolymers can be polymerized by sequential monomer addition, but more often the first block is synthesized, isolated, and... 

Transformations can be achieved not only between different polymerization methods, but also by the same mechanism, using different initiating systems. For example, ATRP can be combined with RAFT polymerization, as both are controlled radical polymerization methods (Scheme 11.41) [170-172]. 

The polymerization of NVK and related monomers was examined using controlled radical polymerization methods, such as atom transfer radical polymerization, single electron transfer, and single electron transfer initiation followed by a RAFT chain transfer [16]. 

The reverse mode in which controlled free radical polymerization techniques are employed as the first step is also possible. The most widely employed controlled radical polymerization methods for this particular transformation are ATRP and NMRP. This is mainly because of the fact that hydroxyl and amino groups, potential initiating sites for the AROP of certain monomers, are compatible with the ATRP and NMRP of vinyl monomers. Table 4 summarizes the examples of this transformation approach. 

Studying the Fundamentals of Radical Polymerization Using ESR in Combination with Controlled Radical Polymerization Methods... 

Living Radicai Poiymerization. Undoubtedly the main advance in block copolymer synthesis in the last decade has been the development of techniques of living radical polymerization (sometimes termed controlled radical polymerization). The principle of controlled radical polymerization methods is to establish a dynamic equilibrium between a small fraction of growing free radicals and a... 

Among the controlled radical polymerization methods discussed here, ATRP is the most applied route for the preparation of telechelics since besides the initiator functionalization, the terminal halogen produced in ATRP can easily be converted to many useful functionalities, eg by nucleophilic substitution (82). 

Cai-Yuan, P. and Chun-I n, H. (2004) Synthesis and characterization of block copolymers prepared via controlled radical polymerization methods. In I.W. Hamley (ed.). Developments in Block Copolymers - Science and Technology. WUey, Chichester, New York, Weinheim, Brisbane, Toronto, Singapore, pp. 71-125. 

This chapter serves as a brief overview of the controlled radical polymerization methods, atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer (RAFT) polymerization, and their utilization in the construction of solution-based stimuli-responsive polymers. The structure/property/behavior relationships of selected systems are discussed relative to changes in pH, tanperature, and electrolyte concentration. Additionally, comprehensive reviews are cited for additional information. 

Kajiwara A. Studying the fundamentals of radical polymerization using ESR in combination with controlled radical polymerization methods. Macromol Symp 2007 248 50-59. 

An alternative and convenient approach that is also highly versatile is the use of polymers prepared via RAFT polymerization as precursors to thiol-capped polymers. RAFT polymerization is the most versatile controlled radical polymerization method in terms of the wide variety of monomers that may be used. As such, the combination of this technology with thiol-ene chemistry offers, arguably, the greatest accessibility to synthetic functional materials. 

The area started to boom after 1994, by which time awareness of controlled radical polymerization methods was rising, when the well-controlled polymerization of acrylates was reported almost simultaneously by the groups of Harwood and Wayland using organocobalt(III) compounds based on glyoxime (cobaloximes) and porphyrins as initiators (Figure While II is a thermal initiator, I needs photo-... 

In the last 15 years, OMRP has proven a robust and reliable method for controlling the polymerization of a variety of monomers. Its advantage, relative to other controlled radical polymerization methods, is in the flexibility of the metal complex, via optimization of the metal and coordination sphere, making the bond strength suitable in principle for... 

The main techniques for synthesis of block copolymers in research labs around the world are presently anionic polymerization and controlled radical polymerization methods. The older technique of anionic polymerization is still used widely in the industrial manufacture of block copolymers. Cationic polymerization may be used to polymerize monomers that eannot be polymerized anioni-cally, although it is used for only a limited range of monomers. A summary of block copolymer synthesis techniques has been provided by Hillmyer [5]. 

Extending controlled radical polymerization methods to the block copolymerization of cyclic vinyl ethers using commercially available monomers is of... 

Cellulose is a highly interesting material as a result of its materials properties, abundance, renewability and low cost. The heterogeneous grafting of cellulose fibers through controlled radical polymerization methods allows preparation of fibers with tailorable properties and built-in functionalities that can act as promising materials for advanced applications [118-121],... 

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