Order and strain in main-chain smectic liquid-crystalline polymers and elastomers.
The layer correlations in main-chain smectic liquid-crystal polymer and elastomer systems have been studied using high-resolution X-ray scattering. In contrast to side-chain smectic polymers, in main-chain systems the polymer chains are oriented parallel to the layer normal. As a result they couple directly to the lamellar structure and any polymer defect is translated into layer distortions. For the homopolymers the resulting X-ray lineshapes are well described by Lorentzians. This is interpreted as an average of algebraically decaying order in domains with dimensions of hundreds of nm and a wide dispersion of sizes. The elastomers show much broader peaks than the correponding polymers. This is attributed to strong non-uniform strain within the finite-size domains due to defects of the layer structure.
de Jeu
W H
WH
FOM Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ, Amsterdam, The Netherlands. dejeu@mail.pse.umass.edu
Obraztsov
E P
EP
Ostrovskii
B I
BI
Ren
W
W
McMullan
P J
PJ
Griffin
A C
AC
Sánchez-Ferrer
A
A
Finkelmann
H
H
D003198:Computer Simulation; D004548:Elasticity; D020724:Elastomers / Q000737:chemistry*; D050866:Liquid Crystals / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D044367:Phase Transition; D013314:Stress, Mechanical
D020724:Elastomers