Superstructure of Main-Chain Liquid Crystalline Polymers

Superstructure of extruded liquid crystalline polmers was studied by electron microscopy,wide angle X-ray diffraction, and polarized infrared spectroscopy. Oriented morphology was developed by shear flow and elongational flow during the extrusion molding. The elongational flow was more effective on orienting polymer chains than the shear flow. The orientation function increased with increasing draw-down ratio, but the increase of orientation function was saturated at higher draw-down ratio. The mechanical properties also depended upon the draw-down ratio and were well correlated with the orientation functions. The orientation distribution was developed inside the extruded materials, and was characterized by polarized FTIR microspectroscopy and polarized reflection infrared spectroscopy. The orientation distribution in the extrudates was discussed in relation to the morphological structure studied by scanning electron microscopy.