SOLID-STATE CROSS POLARIZATION MAGIC ANGLE SPINNING C-13 NMR-STUDY OF THERMOTROPIC AROMATIC POLYESTER CONTAINING A FLEXIBLE SPACER IN THE MAIN CHAIN

The solid-state structure of a thermotropic aromatic polyester containing an aliphatic flexible spacer based on terephthalic acid and 4,4 prime -dihydroxy-1,6-diphenoxyhexane has been investigated by high-resolution solid-state CP/MAS (cross polarization/magic angle spinning) **1**3C NMR. Samples of the polymer with different thermal histories, i. e. , an original sample as obtained by low-temperature solution polymerization and once-melted samples with different cooling conditions have been prepared. For the orignal sample, the solid-state spectrum shows that a conformation of the hexamethylene spacer is all-trans in the plane of the phenoxy group and that the ester linkage is nearby perpendicular to the plane of the aromatic ring.