X-ray diffraction by thermotropic main-chain polymers with side groups. I. rigid polyesters

Thermotropic poly(sulfonyl hydroquinone terephthalate) with either H or CH₃ in the lateral substituent was aligned by drawing from nematic melts. Virtually identical x-ray intensity distributions were recorded consisting of “disks” of intensity periodically spaced along the meridian and concentric rings of intensity lying in the equatorial plane of reciprocal space. They correspond to what is expected for the hexagonal packing of parallel periodic chains that are randomly displaced along the chain axes. Using interactive graphics, appropriate molecular models were deduced in conformity with the observed diffraction intensities.