STRUCTURAL ASSESSMENT OF LIQUID-CRYSTALLINE SIDE-CHAIN POLY(VINYL ETHER)S - DEPENDENCE ON TERMINAL GROUP, ORIENTATION AND TEMPERATURE

Oriented and non-oriented samples of two liquid-crystalline side-chain poly(vinyl ether)s, poly{4-[11-(vinyloxy)undecyloxy]-4-cyanophenylbenzoate} (poly(1)) and poly{4-[11-(vinyloxy)undecyloxy]-4-ethoxy-phenylbenzoate} (poly(2)), have been studied by small-angle and wide-angle X-ray scattering techniques, polarized light microscopy and differential scanning calorimetry. The terminal group of the mesogenic unit played an important role in the organization of the side chains. With increasing temperature, poly(1) exhibited a smectic C, a transitional ordered smectic, a smectic A and finally an isotropic phase, whereas poly(2) showed a crystal B, a smectic A and an isotropic phase. Both polymers showed a glass transition at 310 K. The global alignment of the mesogenic groups did not affect the internal order of the smectic phases.