ORIENTATIONAL ORDER IN LIQUID-CRYSTAL SOLUTIONS OF POLYHEXYLISOCYANATE .2. DEUTERIUM NUCLEAR-MAGNETIC-RESONANCE

The concentration dependence of the order parameter was measured for l iquid crystal solutions of deuterated samples of polyhexylisocyanate o f two molecular weights in two solvents, chloroform and toluene. Trend s in and values of order parameters determined from deuterium nuclear magnetic resonance (DNMR) spectroscopy for this semiflexible polymer w ere analyzed in terms of a recent modification [DuPre and Yang, J. Che m. Phys. 94, 7466 (1991)] of the Onsager theory that takes into accoun t macromolecular flexibility and the higher solute densities character istic of these polymer liquid crystals. Computer simulation of DNMR sp ectra with the consideration of internal flexibility of the polymer ma in chain was performed also to interpret unusual line shape features o bserved in liquid crystal solutions of this polymer.