Highly branched “comb-shaped polymers

It has been hypothesized by Graessley (30) and others (3, 31) that the g1/2 rule is applicable to star-shaped and slightly branched polymers whereas the g372 rule describes the behavior of highly branched "comb-shaped polymers for which [rj] B/ [y] l < 0.5. The results of this study indicate that the g1/2 rule in combination with Equation 11 adequately represents the random trifunctionally and tetrafunctionally branched... 

Homopolymerization of macromonomer provides regular star- or comb-shaped polymers with a very high branch density as shown in Fig. 1 a,c,e. Such polymacromonomers, therefore, are considered to be one of the best models for understanding of branched architecture-property relationships. Their properties are expected to be very different from the corresponding linear polymers of the same MW both in solution and the bulk state. Indeed, during the past decade, remarkable progress has been accomplished in the field of static, dynamic, and hydrodynamic properties of the polymacromonomers in dilute and concentrated solutions, as well as by direct observation of the polymers in bulk. 

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