^(13)C-NMR chemical shifts of model compound of a novel side chain liquid crystalline polymer, poly 2.5-his (4-alkoxybenzoyloxy) styrene , have been assigned in this study. Moreover, by using high-resolution solid-sta...^(13)C-NMR chemical shifts of model compound of a novel side chain liquid crystalline polymer, poly 2.5-his (4-alkoxybenzoyloxy) styrene , have been assigned in this study. Moreover, by using high-resolution solid-state CP/MAS (cross polarization/magic angle spinning) technique, the spectrum shows that in the crystalline state the ester linkage has a conformation nearly perpendicular to the either side of ring planes, and that the alkoxy groups are not fully in zigzag form. The possible conformational changes around the mesogens from the solid state to the mesophase are discussed.展开更多
Tonelli’s γ effect in Macromolecules, 11 （1978） 565, and Flory’s rotational isomeric state model of polypropylene in Macromolecules, 8 （1975） 687, were employed to calculate the 13C-NMR chemical shifts expected...Tonelli’s γ effect in Macromolecules, 11 （1978） 565, and Flory’s rotational isomeric state model of polypropylene in Macromolecules, 8 （1975） 687, were employed to calculate the 13C-NMR chemical shifts expected of methyl carbon in the various stereoisomers of atactic polypropylene. The probabilities of bonds producing γ展开更多
One may imagine two ways in which a small amount of raee,mie configuration r may be introduced into an isotactic chain: (ⅰ) a template propagation error, in which rr resonance may
文摘^(13)C-NMR chemical shifts of model compound of a novel side chain liquid crystalline polymer, poly 2.5-his (4-alkoxybenzoyloxy) styrene , have been assigned in this study. Moreover, by using high-resolution solid-state CP/MAS (cross polarization/magic angle spinning) technique, the spectrum shows that in the crystalline state the ester linkage has a conformation nearly perpendicular to the either side of ring planes, and that the alkoxy groups are not fully in zigzag form. The possible conformational changes around the mesogens from the solid state to the mesophase are discussed.
文摘Tonelli’s γ effect in Macromolecules, 11 （1978） 565, and Flory’s rotational isomeric state model of polypropylene in Macromolecules, 8 （1975） 687, were employed to calculate the 13C-NMR chemical shifts expected of methyl carbon in the various stereoisomers of atactic polypropylene. The probabilities of bonds producing γ
文摘One may imagine two ways in which a small amount of raee,mie configuration r may be introduced into an isotactic chain: (ⅰ) a template propagation error, in which rr resonance may
