STUDY ON BLENDS OF LIQUID-CRYSTALLINE COPOLYESTERS WITH POLYCARBONATE.3. MECHANICAL-PROPERTIES OF COMPATIBILIZED BLENDS

Blends of liquid crystalline poly(oxybenzoate-co-oxynaphthalate) (Vect ra A950) and polycarbonate (PC) were prepared by adding a compatibiliz er to the two polymers in a melt-blending process. The compatibilizer was based on controlled transesterification between synthesized poly(o xybenzoate-co-terephthalate) (40/60) and PC. The compatibilizer exhibi ted birefringence, and its thermal property was analyzed by differenti al scanning calorimetry. The maximum increase in tensile modulus and t ensile strength of these compatibilized Vectra blends were 24% and 54% , respectively, as compared with those of binary Vectra blend without compatibilizer resulting from an injection-molding process. The tensil e properties of the compatibilized Vectra blends decreased once the co ncentration of the compatibilizer exceeded 2 phr. (C) 1997 John Wiley & Sons, Inc.