Copolymerizable units

Connection of dendrimers via treatment with multifunctional cross-linking-type reagents such as the addition of polyhalides to amine-terminated dendrimers 78 results in randomly positioned dendritic assemblies. Dendrimers have also been bridged by the incorporation of copolymerizable units into reactions with dendrimers possessing polymerizable, terminal olefins. 79,80 ... 

The product of the polymerization constants, riT2, is very frequently used as an index for evaluating the alternating tendency in binary copolymeriz-ation/" In fact, the reciprocal of the product rir2 is often called the alternation tendency index. The ideal (random) copolymerization condition exists for the case / i/ 2 = Where ri and r2 are very low and the rir2 product tends to zero the alternating tendency increases.The product r r2 can be zero in two cases—where one or both reactivity ratios are zero. Where r — 0, the copolymer chain is built of isolated Mi units separated by sequences of M2 monomer units. Strictly alternating copolymer would be obtained when both / i and V2 are zero. The second condition is often found for MA copolymerizations, as described in Chapter 10. Where ri > 1, the polymer is richer in Ml monomers than the monomer feed. For ri < 1, the opposite holds. 

They show very low copolymerizability of VC with BA and high reactivity of VC with VAc. VAc copolymerizes slightly with BA but strongly with VC. Combination of all monomers gave copolymers with homogeneous structure and rich in VC units from the beginning of polymerization. 

Copper-based ATRP is a robust broadly applicable method of CRP that provides control over the MW, MWD, composition, molecular architecture, and chain end functionalities of a spectrum of polymeric materials prepared by copolymerization of a broad range of radically copolymerizable monomers. ATRP provides unique access to various organic/inorganic hybrids and also biorelated materials. ATRP has been commercialized in the United States, Europe, and Japan in 2004. Some current and forthcoming applications include specialty materials for coatings, dispersants, sealants, health and beauty produas, as well as materials for optoelectronic and biomedical areas. 

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