Induced gamma -> alpha crystal transformation in blends of polyamide 6 and liquid crystalline copolyester

Abstract

The equilibrium melting temperatures and the induced gamma --> ct crystal transformation in blends of random liquid crystalline copoly(oxybenzoate-ethylene terephthalate) at molar ratio 60/40 (P64) and polyamide 6 (PA6) under different thermal treatments were investigated with differential scanning calorimetry and wide-angle X-ray diffraction, respectively. It was found that the equilibrium melting temperatures of P64/PA6 blends depended strongly on the amount of P64, and the presence of a small amount of P64 in PA6, around 5%, induced additional crystallization of the or-form crystal in the quenched PA6. Moreover, the onset temperature for the gamma --> alpha crystal transformation in the 5/95 P64/PA6 blend was reduced by 30 degrees C as compared to that in the pure PA6 case (160 degrees C vs 130 degrees C).