| Abstract
| - A series of well-defined dumbbell copolymers of (PBd)32PS(PBd)32 type, with the samepolystyrene (PS) connector (10 600 g/mol) and 32 polybutadiene (PBd) branches of varying molecularweight (1200, 5000, 15 000, 43 000 g/mol) on each end, were synthesized, and their viscoelastic propertieswere investigated. For the three larger branches (above the entanglement molecular weight), theirrelaxation controls the dynamics of the macromolecular dumbbells, which exhibit starlike behavior. Forthe shorter branch, the backbone fraction (and thus its relaxation) is nonnegligible, and it should beconsidered in the assessment of the dynamics. A general map of the relaxation of such complex modelbranched polymers is proposed, where the dumbbell dynamics depend on the branch size for large branches(as in the star case) or on the total molecular size for short branches.
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