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.

Includes erratum: Eur. Phys. J. E 25 (2008)117-118
Eur. Phys. J. E

de Jeu, W. H., Obraztsov, E. P., Ostrovskii, B. I., Ren, W., McMullan, P. J., Griffin, A. C., … Finkelmann, H. (2007). Order and strain in main-chain smectic liquid-crystalline polymers and elastomers. Eur. Phys. J. E, 24, 399–409. doi:10.1140/epje/i2007-10254-8