POST EXTRUSION HOT DRAWING OF POLYCARBONATE LIQUID-CRYSTALLINE POLYMER BLENDS

The post extrusion hot drawing of polycarbonate/liquid crystalline pol ymer (PC/LCP) blends, over the entire composition range, was studied. The extruded filament morphology and elastic modulus were followed as a function of blends composition, initial phase morphology, and draw r atio (DR). Hot drawing was found to cause further orientation to the a lready existing partially oriented LCP phase at the die exit, as refle cted by the increased blends modulus. The additional orientation depen ds on the initial filaments structure, the blend composition, and the DR. Moreover, the orientability of the LCP phase is much higher, simil ar to that of neat LCP, for blends in which the LCP forms the continuo us phase. In low LCP content blends, a critical DR was identified, bey ond which the LCP fibrils undergo fragmentation and voids at the fibri ls/matrix interface are formed, resulting in a decrease in the drawn f ilament modulus.