Liquid-crystal polymer fiber production and reinforcing in ribbons of poly(ether imide)/vectra-B blends

Blends of poly(ether imide) (PEI) with a liquid-crystal polymer (Vectra-B950) were extruded into ribbon. Two PEI-rich compositions at three different draw ratios were obtained, and the miscibility and morphology of the blends analyzed. The tensile properties of the ribbons were determined, both in the processing and in the perpendicular direction and were compared with those of the pure PEI. Results showed that PEI/Vectra blends are immiscible and that complex structures were obtained as a consequence of extrusion. The blend composition and the draw ratio determined to a great extent the mechanical properties of the blends. The interfacial adhesion between blend components is low, but enough to break the LCP fibers when significant aspect ratios are attained.