Branched macromolecules arborescent polymers

Arborescent homopolymers are interesting, among others, as model compounds to study the properties of branched macromolecules beyond other systems such as star-branched polymers and microgels, due to their high branching functionalities and the extensive control achieved over the architecture (branching density, side-chain molecular weight) of the molecules. The synthesis of arborescent styrene homopolymers and some of their physical properties will be discussed first. 

Gauthier, M. and Mdller, M. Uniform highly branched polymers hy anionic grafting Arborescent graft polymers. Macromolecules, 24, 4548, 1991. 

Figure 1 Macromolecular architectures linear macromolecular chains (homopolymer, block-copolymer and statistical copolymer [14]), brushed-polymer (= linear chains attached to a polymer-chain brush-polymer, brush-copolymers [14]), star polymer [4], mikto-star-polymer [16], arborescent graft polymer (=repeated grafting of linear chains on a macromolecule [17,18]), dendrimer (= maximally branched, regular polymer [15])...

Highly branched, so called hyperbranched macromolecules have recently attracted interest, because of their interesting properties, which closely resemble those of dendrimers. Vinyl monomers with pendant initiating moieties, for example, 3-(l-chloroethyl)-ethenylbenzene, have been reported to give rise to hyperbranched polymers in a process termed self-condensing vinyl polymerization [253]. Hyperbranched PIBs have been synthesized by cationic copolymerization of 4-(2-methoxyisopropyl)styrene and IB [254]. Using a similar approach the preparation of arborescent block copolymers of IB and St (arb-PIB-h-PSt) has also been reported (see above) [226]. 

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