Abstract
Multi-arm star polystyrenes with various lengths and number of arms were synthesized, and their dynamic viscoelastic properties were investigated in the molten state. The master curves of the storage modulus for the multi-arm stars showed a shoulder at low frequencies, suggesting that a new mechanical relaxation exists at the long time scales after completion of entanglement relaxation. The enhancement of the zero-shear viscosity compared with the regular star polymers was also observed for the multi-arm star polymers.
