Star-shaped polymers having PEO arms

The syntheses, properties and some applications of star-shaped polymers with arms constituted of homo- or copolymers of poly(ethylene oxide) (PEO) is reviewed. The general description of the methods of syntheses, including “arm first” and “core first” procedures, of various types of star-shaped polymers is given as an introduction, without a detailed analysis of the involved chemical procedures. Then, the synthesis of star polymers (including miktoarm stars) with strictly defined as well as with varying number of arms and having cores formed from small and/or large molecules: branched, cross-linked, dendritic, etc., is described. Examples of the large number of various structures of star-shaped PEO polymers described in the literature are presented in a series of tables. Recently elaborated procedure for the synthesis of the star-shaped PEO polymers using hydroxyl terminated precursors of arms and diepoxides as core forming molecules is described in more detail because the method has a general significance and may be applied for the synthesis of a variety of star polymers. Interest in star-shaped and branched systems based on poly(ethylene oxide) (PEO) is mainly motivated by their potential applications in the biomedical and pharmaceutical areas. Therefore, the properties and applications of PEO stars are also reported, as, e.g., drug carriers, surface modifiers, and components of membranes, and/or hydrogels.