We have synthesized a series of liquid crystalline/isotropic block copolymers with narrow
molecular weight distribution and with well-defined chemical structure. Block volume fractions were
varied systematically. The domain structure of these compounds was determined by means of small-angle X-ray scattering. Spherical, cylindrical, and lamellar morphologies were observed with the liquid
crystalline (LC) block in the matrix or in the domain, respectively. The polymers are strongly segregated,
and no order-to-disorder transition is found up to 170 °C. DSC and polarized microscopy data reveal that
the mesomorphic behavior of LC blocks is only slightly influenced by copolymer composition and is basically
characterized by the sequence g/∼35 °C/n/∼120 °C/i. The rotational dynamics over a broad temperature
and frequency range was studied using dielectric spectroscopy. The LC block reveals two cooperative
modes assigned to the segmental relaxation (α process) and to the side chain rotation as a whole (δ process).
A confinement effect is visible in the shift of both relaxation times to lower values for domain sizes less
than 20 nm. The effect is stronger for 2D than for 1D confinement geometry. It is small compared to
similar effects found for free-standing thin polymer films. For copolymers with alternate lamellae or LC
cylindrical microdomains, a Maxwell−Wagner polarization was observed in addition to the α and δ
processes.