Chain Dynamics of Styrene Polymers Studied by the Fluorescence Depolarization Method

Abstract

The local motion of polystyrenes in dilute solutions was examined by the fluorescence depolarization technique. The samples, polystyrene (PS), poly(α-methylstyrene) (PαMS), and poly(p-methglstgrene) (PpMS), were labeled with the fluorescent probe anthracene in the middle of the main chain. The relaration time of their local motion in dilute solutions was examined by fluorescence anisotropy measurement. The activation energy of the relaxation time of the polymer chain, E * , was also evaluated by the theory of Kramers'diffusion limit. There was a close correlation between the reduced relaxation time, T m /η, or its activation energy and the chain expansion factor; i.e., both the reduced relaxation time and the activation energy decrease as the solvent quality becomes better