Combinations of Click Chemistry and ATP as Well as ATP and RAFT Polymerizations
In the last few years, “click reactions,” as termed by Sharpless et al. [280] received attention due to their high specificity, quantitative yields, and good fidelity in the presence of most functional groups. The “click chemistry” reaction includes a copper-catalyzed Huisgen dipolar cycloaddition reaction between an azide and an alkyne leading to 1,2,3-triazole. Recent publications on this “click reaction” indicate that it is a useful method for preparation of functional polymers [281].
Matyjaszewski and Gao synthesized functional polymers by combining ATRP and the "click reactions." They also prepared telechelic polymers, star polymers and brush polymers [282]. Forma-tion of telechelic polymers was illustrated as follows:
Also, a synthesis of an iniferter that consists of a trithiocarbonate moiety and two bromine chains ends was reported [282]. This iniferter was used to conduct either independently or concurrently both ATRP and reversible addition-fragmentation chain transfer polymerizations. The iniferter was illustrated as follows:
RAFT polymerizations with this iniferter of N-butyl acrylate and styrene yielded polymers with M/ Mn equal to 1.15 and 1.16 respectively. Polymerization of methyl methacrylate, however, yielded a polymer with a broad M/M ratio. On the other hand, polymerization in the presence of CuBr/TMPA by ATRP exclusively through the bromine chain ends yielded a polymer with narrow M/M ratio.
