Storage and Loss Moduli of Model Branched Systems

3 Storage and Loss Moduli of Model Branched Systems 

Struglinski et al. [97] and Watanabe et al. [98] studied blends of linear and star polymers and proposed empirical mixing rules for such systems, and Roovers etal. [99,100] have studied the rheology of stars with very large numbers of arms. 

By grafting macromonomers onto a polymer backbone (see Section 3.4) a great variety of comb-like structures have been prepared and studied using rheometry. Bailly et al. [ 102 ] made combs ( bottle brushes ) having a 98% grafting density. They found that their plots of storage and loss moduli versus frequency followed power-law dependencies over five decades of frequency, and the power on the frequency was 0.6. 

Houli et al. [107] made model dumbbell polymers by attaching multi-arm polybutadiene stars onto the ends of a polystyrene connector. If the connector made up less than 10% of the molecule, the behavior was star-like. Finally, we mention that Miros etal. [108] used short polyethylene chains as an ideal solvent for multiarm stars. 

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