DIELECTRIC STUDIES ON THE DYNAMICS OF POLYMER-CHAINS IN VARIOUS ENVIRONMENTS

Stockmayer's type-A chain such as cis-polyisoprene (PI) having dipole moments aligned parallel to the chain contour exhibits slow dielectric response, reflecting fluctuation of the end-to-end vector of the chai n (dielectric normal modes). This article intends to review our own wo rk on dielectric spectroscopy using PI as a probe for studying dynamic s of large scale motion of the probe chain in binary blends with polyb utadiene (PB) and in block copolymers with PB or with polystyrene. Thr ough such studies we were able to see the features of polymer chain dy namics in various environments: Rouse-Zimm-like dynamics in overlappin g-but-unentangled regimes, reptation with and without accompanying con straint release, behaviour of a subchain incorporated into block copol ymers with miscible segments, and dynamics of polymer brushes in stron gly segregating block copolymers in bulk and in solutions.