Star-branched oligomers

Nelson, W, and Heckelsberg, L. E, Synthetic lubricants star-branched oligomers via metathesis, Ind. Eng. Chem. Prod. Res. Dev., 22, 178, 1983. 

Anionic deactivation methods have proved their efficiency in the synthesis of star-branched oligomers where the central core is obtained upon reaction of oligobutadienyllithium with diesters and epoxidized soybean oil [28]. 

Electropolymerization of star-shaped oligomers 5.18a-c resulted in the formation of highly redox active, cross-linked hyperbranched polymers which led to systems with good conductivities, indicating the presence of multiple pathways for charge carriers provided by the branching units [472],... 

In the previous sections, star-shaped polymers were discussed. In this section, highly branched oligomers or polymers, as distinct from simple star-shaped polymers, will be considered. Several excellent, recent reviews are available on this subject [10-14,47,64,65]. 

Depending on the composition of the monomer feed and the polymerization procedure, different types of heterogeneities may become important. For example, in the synthesis of tailor-made polymers telechelics or macromonomers are frequently used. These oligomers or polymers usually contain functional groups at the polymer chain end. Depending on the preparation procedure, they can have a different number of functional end groups, i.e. be mono-, bifunctional, etc. In addition, polymers can have different architectures, i.e. they can be branched (star- or comb-like), and they can be cyclic. 

Figure C2.1.2. Polymers with linear and nonlinear ehain arehiteetures. The nonlinear polymers ean have branched chains. Short chains of oligomers can be grafted to the main chain. The chains may form a star-like structure. The chains can be cross-linked and form a network.

Fig. 1.5. Polymers with non-linear architectures polymer with short-chain and long-chain branches (A), polymer with grafted oligomer side chains (B), star polymer (C), network of cross-linked chains (D)...

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