Long chain branch polymer chain dimensions: application of topology to theZimm-Stockmayer model

An explicit topological approach to the dimensions of LCB polymers is prese nted. It is based on the Wiener number, a topological descriptor which is s hown in this study to be related to the topological radius of the macromole cule, the mean-square radius of gyration, the g-ratio, and the intrinsic vi scosity within the Rouse-Zimm range. The new theory enables the treatment o f the highly complex hyperbranched polymers, which are difficult to handle by the classical theory of Zimm and Stockmayer. The agreement with the meas ured g-values of model polyethylenes, synthesized by Hadjichristidis et al. , is fairly good for star-like polymers and satisfactory for pom-pom type o f structures, whereas for crowded comb-type species the calculated g-values are underpredicted. Extension of the approach is shown to cyclic structure s for which the Kirchhoff number replaces the Wiener number. (C) 2001 Elsev ier Science Ltd. All rights reserved.