作者:J. Geng, X. Zhao, E. Zhou, G. Li,* J. W. Y. Lam, B. Z. Tang
关键字:Liquid-crystalline polymer, Polyacetylenes, Shear orientation
论文来源:期刊
具体来源:Polymer 2003, 44, 8095-8102
发表时间:2003年
Mesomorphic properties of a side chain liquid crystalline polyacetylene, poly(11-{[(40-heptyloxy-4-biphenylyl)carbonyl]oxy}-1-undecyne) (PA9EO7), are investigated using polarized optical microscope, X-ray diffraction, and transmission electron microscope. Polymer PA9EO7 forms enantiotropic smectic A and smectic B phases. It also exhibits an additional high order smectic phase, a sandwich structure consisting of different molecular packing of biphenyl mesogenic moieties from that of alkyl spacers and terminals, when it is prepared from its toluene solution. Shearing the polymer film at its smectic A phase generates banded texture with the alignment of the backbones parallel to the direction of shear force. While at its high order smectic phase, the mesogen pendants of the polymer are arranged parallel to the direction of shear. The different mesomorphic behaviors arise from different molecular alignments influenced by the fluidity.