Photoinitiated RAFT polymerization

The first successful photoinduced RAFT pol5mierization at low temperature has been reported by Pan et al. [ifOU 02] who polymerized St, 

Diagram 3.7. The proposed mechanism of reversible termination polymerization 

Diagram 3.8. Various RAFT agents employed in photoinitiated RAFT polymerizations 

Vinyl acetate (VAc) is one of the most difficult monomers to polymerize in a controlled/living manner. It must be polymerized by a radical mechanism and only a few studies have been reported with well-defined MW and PDI [lOV 03, YAM 04, KOU 08, KOU 08, WAK 01, YAN 10, 

Diagram 3.9. Key components of the UV-induced RAFT polymerization of vinyl acetate 

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Several groups have also reported the synthesis of polystyrene [RAN 07], poly(methyl methacrylate) [VEE 11] and poly(styrene-o/t-maleic anhydride) [WU 03] via photoinitiated RAFT polymerization. However, this method exhibits some limitations such as low conversions even at long... 

In RAFT polymerization, the original radicals were commonly generated by traditional methods hke azo- or photoinitiators as well as gamma radiation (Quinn et al., 2002). A propagating oligomeric chain is formed when the initial radical reacted with the monomer. The main component in PJVFT... 

Very active is the area of macromolecular chemistiy, with applications that range from new photoinitiators to new polymerization mechanisms (RAFT, reversible addition-fragmentation), useful for obtaining advanced microparticle design. ... 

Photo-induced polymerization of hydroxypropyl-P-CD/methyl methacrylate complex, i.e. HP-P-CD/MMA was performed in aqueous solution, at room temperature with Irgacure 2959, i.e. 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone serving as a photoinitiator [75]. The atom transfer radical polymerization (ATRP) and reversible addition fragmentation chain transfer (RAFT) [76] methods are also used to perform polymerization of the CD/guest monomer complexes in aqueous solutions. 

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