Post extrusion hot drawing of polycarbonate liquid crystalline polymer blends

The post extrusion hot drawing of polycarbonate/liquid crystalline polymer (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 ratio (DR). Hot drawing was found to cause further orientation to the already existing partially oriented LCP phase at the die exit, as reflected by the increased blends modulus. The additional orientation depends on the initial filaments structure, the blend composition, and the DR. Moreover, the orientability of the LCP phase is much higher, similar to that of neat LCP, for blends in which the LCP forms the continuous phase. In low LCP content blends, a critical DR was identified, beyond which the LCP fibrils undergo fragmentation and voids at the fibrils/matrix interface are formed, resulting in a decrease in the drawn filament modulus.