6 research outputs found
Dynamics of end-linked star polymer structures
In this work we focus on the dynamics of macromolecular networks formed by
end-linking identical polymer stars. The resulting macromolecular network can
then be viewed as consisting of spacers which connect branching points (the
cores of the stars). We succeed in analyzing exactly, in the framework of the
generalized Gaussian model, the eigenvalue spectrum of such networks. As
applications we focus on several topologies, such as regular networks and
dendrimers; furthermore, we compare the results to those found for regular
hyperbranched structures. In so doing, we also consider situations in which the
beads of the cores differ from the beads of the spacers. The analytical
procedure which we use involves an exact real-space renormalization, which
allows to relate the star-network to a (much simpler) network, in which each
star is reduced to its core. It turns out that the eigenvalue spectrum of the
star-polymer structure consists of two parts: One follows in terms of
polynomial equations from the relaxation spectrum of the corresponding
renormalized structure, while the second part involves the motion of the spacer
chains themselves. Finally, we show exemplarily the situation for copolymeric
dendrimers, calculate their spectra, and from them their storage and the loss
moduli.Comment: 15 pages, 11 eps-figures include