Spacers living polymerization

Polymer brushes can be obtained by metal-mediated living radical polymerization from the initiator moiety confined to the surface of a substrate via spacers. The surface-initiated living polymerization can control the thickness and the density of brushes the former is regulated by brush s chain length and... 

The effect of varying the nature of the spacer from hydrocarbon to siloxane is starting to be investigated using living polymerizations [28]. However, these polymers have not been characterized yet. 

Such a synthesis is feasible in living cationic polymerization of vinyl ethers [208], For bifunctional vinyl ethers (20), a series of compounds are examined (Scheme 11), among which 20a turned out the best, probably due to the appropriate rigidity and length of the spacer. By adjusting reaction... 

Immobilized catalysts have been studied in metal-catalyzed living radical polymerization for, in part, easy removal of the catalysts from the products. In most examples, the catalytic metal centers are attached to solid supports, such as silica gel and polystyrene beads, via spacers and/or coordinating ligands (Figure 7). The central metals thus far employed include copper and ruthenium. 

Halogen compounds with two reactive carbon-halogen bonds can be bifunctional initiators for metal-catalyzed living radical polymerizations to give telechelic polymers. The effective bifunctional initiators include MI-1 to MI-26 with various spacers between the initiating sites. 

Functional groups can also be introduced in the spacer units. Bifunctional initiators with bipyridine units such as MI-17 and MI-18 induced the living radical polymerizations of styrene and MMA, respectively, with copper catalysts to give polymers that carry a coordination site at the middle of the chain.87,333 These polymers can be connected together into star polymers with a ruthenium cation at the core, where the arm numbers are varied among three, four, five, and six in combination with the polymers obtained from the monofunctional initiator with a bipyridine unit (FI-21 and FI-22 Figure 13).416 A... 

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