EFFECT OF DRAWING ON THE MORPHOLOGY AND PROPERTIES OF LCP/ABS BLENDS

Polymer blends of a copolyester liquid crystalline polymer (LCP) and ABS were prepared by melt blending with a twin-screw extruder and the extrudate were obtained at different draw ratio. The morphology and mechanical properties of the extrudate were studied as functions of LCP content and draw ratio.

The mechanical properties (ultimate tensile strength and Young's modulus) of the LCP blends increased with both LCP content and the draw ratio, whereas those of the ABS extrudate was not influenced by draw ratio. It indicated that the mechanical property enhancement in the blends was due to the change of LCP structure. The morphology study revealed that at a given LCP concentration, the L/D ratio of the LCP fibrils increased with draw ratio. At higher LCP concentrations, the LCP fibril diameter increased at a given draw ratio, due to coalescence of LCP fibrils.

This study showed that hot drawing was an effective way to promote the LCP fibrillation in LCP-based polymer blends and extensional stress was responsible for the fibril formation.