Copolymers, comb shape synthesis

Free-radical copolymetization has been used extensively for the synthesis of graft copolymers or comb-shaped polymers using the grafting through strategy. " The references given... 

Metallocenes or late transition metal catalysts were iiKxeas-ingly utilized over the years for the (co)polymetization of olefins including the synthesis of graft copolymers. In this last case coordination polymerization had to be combined with other polymerization processes to give access to macromonomets. However, only a few examples of coordination homopolymer-ization or copolymerization of macromonomets aimed to design comb-shaped polymers were described in the literature. In the following these examples will be described briefly. 

Figure 19 Synthesis of a comb-shaped PS with two branches. This can be extended to graft copolymers with exact spacing of side chains. Reproduced from Hirao, A. Watanabe, T. Kurokawa, R. Macromolecules 42, 3973. " ...

Since there is no chain transfer involved, preparation through living polymer results in a narrow distribution of molecular weight. It is the best way to synthesize di- and triblock copolymers, star-shaped and comb-shaped polymers, and homopolymers with high molecular weight. The following is an example of the synthesis of di- and triblock copolymers ... 

Fukushima et al ° applied TU-mediated organocatalyzed polymerization to maaomolecular engineering. For instance, they reported the synthesis of comb-shaped block copolymers made of PEO as the hydrophilic component and a statistical copolycarbonate as hydrophobic backbone carrying... 

Yuan et al. [165] reported the synthesis of well-defined dendrimer-star, block-comb polymers by the combination of living ring-opening polymerization and atom transfer radical polymerization on the basis of a dendrimer polyester. Star-shaped dendrimer PCLs were synthesized by the bulk polymerization of e-caprolactone with a dendrimer initiator. The dendrimer PCLs tiien were converted into macroinitiators via esterification with 2-bromopropionyl bromide. And the star-block copolymer dendrimer poly(s-caprolactone)-block-poly(2-hydroxyethyl... 

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