O. Francescangeli et al., HYBRID LIQUID-CRYSTALLINE BLOCK-COPOLYMERS .2. X-RAY-DIFFRACTION ANALYSIS OF POLYESTER-POLYMETHACRYLATE BLOCK-COPOLYMERS, Polymer Journal, 28(3), 1996, pp. 193-197
The molecular organization in the smectic mesophases of a series of ma
in-chain/side-chain block copolymers was studied by X-ray diffraction
on oriented specimens. The main-chain and the side-chain blocks were p
hase-separated and gave rise to two coexisting smectic domains with di
fferent layer periodicities. The orientation of the smectic planes in
the distinct domains with respect to the fiber axis was very different
in the various samples and depended on the relative length of the blo
cks. In the presence of relatively short side-chain blocks, the orient
ation of the main-chain block dominated and the smectic planes of the
side-chain block were forced to be parallel to those of the main-chain
block and perpendicular to the fiber axis. In contrast, when the side
-chain block was sufficiently long it imposed its own orientation to t
he main-chain block. In this case, the smectic planes of the main-chai
n block were oriented parallel to those of the side-chain block and to
the fiber axis.