Hyperbranched materials structural characterizations

Dendritic macromolecules exhibit compact globular structures which lead to their low viscosity in the melt or in solution. Furthermore, dendritic macromolecules are characterized by a very large number of available functional groups, which lead to unprecedented freedom for changing/tuning/tailoring the properties of these multivalent scaffolds via complete or partial derivatization with other chemical moieties. All these features have contributed to multidisciplinary applications of these unique macromolecular structures in recent years 6, 7). The development of efficient synthetic routes in recent years has given rise to a virtually unlimited supply of commercially available dendritic polymers, at very affordable price. The transport properties of hyperbranched and dendritic polymers have recently attracted attention as potentially new barrier and membrane materials 8-9). 

In this chapter we consider the properties of synthetic polymers. First, the main techniques of polymer synthesis are outlined (Section 2.2). Then the conformation of polymer molecules is discussed in Section 2.3. We move on to a summary of the main methods for characterization of polymeric materials in Section 2.4. Then the distinct features of the main classes of polymer are considered, i.e. solutions (Section 2.5), melts (and glasses) (Section 2.6) and crystals (Section 2.7). Then the important properties of plastics (Section 2.8), rubber (Section 2.9) and polymer fibres (Section 2.10) are related to microscopic structure and to rheology. Polymer blends and block copolymers form varied structures due to phase separation, and this is compared and contrasted for the two types of system in Section 2.11. Section 2.12 is concerned with dendrimers and hyperbranched polymers. Section 2.13 and 2.14 deal with polyelectrolytes and (opto)electronic polymers respectively. 

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