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, 4-[11-(vinyloxy)undecyloxy]-4-cyanophenylbenzoate } (poly(1)) and [11-(vinyloxy)undecyloxy]-4-ethoxy-phenylbenzoate} (po ly(2)), have been studied by small-angle and wide-angle X-ray scatteri ng techniques, polarized light microscopy and differential scanning ca lorimetry. The terminal group of the mesogenic unit played an importan t role in the organization of the side chains. With increasing tempera ture, poly(1) exhibited a smectic C, a transitional ordered smectic, a smectic A and finally an isotropic phase, whereas poly(2) showed a cr ystal B, a smectic A and an isotropic phase. Both polymers showed a gl ass transition at 310 K. The global alignment of the mesogenic groups did not affect the internal order of the smectic phases.