MODULATION OF SUPRAMOLECULAR STRUCTURE OF LINEAR POLYURETHANE SYSTEMSBY ADDITION OF LIQUID-CRYSTALLINE POLYMERS IN THE MOLECULAR MISCIBILITY RANGE

The peculiarities of domain structure of segmented polyurethane-urea/l iqid-crystalline polyester (PU/LCP) blends were studied in the LCP con centration range of 1-10%, with different lengths of the flexible moie ty. Small- and wide-angle X-ray scattering (SAXS and WAXS) and differe ntial scanning calorimetry were used. The position of the SAXS maximum changes discontinuously with increasing LCP concentration. We suggest that the rigid fragments of the LCP tend to be incorporated into the rigid domains of the PU component with the restriction that only each third or fourth fragment is involved. The part of the LCP molecule tha t fits in the space between rigid PU domains is stretched and determin es the interdomain distance.