Rheology and Solution Properties of Dendrimers

Dendrimers and Other Dendritic Polymers. Edited by Jean M. J. Frechet and Donald A. Tomalia 2001 John Wiley Sons Ltd 

2 ARCHITECTURAL FEATURES OF DENDRIMER MOLECULES THAT AFFECT THEIR RHEOLOGICAL BEHAVIOR 

Generation Number of end groups Molecular weight a/ H, A Tr °c Number of end groups Molecular weight RJRn, A Tv °C Number of end groups Molecular weight Ro/Rh, T °C 

1 Data for PAMAMs from refs 3, 5, 40 and from Amis, E. et al, presentation at 29th ACS Central Regional Meeting, Midland, MI, 28-30 May, 1997 for PPIs from ASTRAMOL web page at www.dsm.nl and for PBzEs from ref. 49. 

dendrimers exhibit a unique combination of (a) high molecular weights, typical for classical macromolecular substances, (b) molecular shapes, similar to idealized spherical particles and (c) nanoscopic sizes that are larger than those of low molecular weight compounds but smaller than those of typical macromolecules. As such, they provide unique rheological systems that are between typical chain-type polymers and suspensions of spherical particles. Notably, such systems have not been available for rheological study before, nor are there yet analytical theories of dense fluids of spherical particles that are successful in predicting useful numerical results. 

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P.R. Dvomic and S. Uppuluri. Rheology and solution properties of dendrimers, in Dendrimers and Other Dendritic Polymers. J.M. J. Frechet and D.A. TomaUa, Eds. John Wiley Sons West Sussex, pp. 331 -358, 2001. 

Compared to dilute solution viscometry and to some extent to bulk rheology, the flow properties of dendrimers in concentrated solutions have been the least investigated area of dendrimer rheology. In fact, with the notable exception of some recent data on generation 4 PPI in water [22] the only [32] reported... 

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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