Effect of the liquid-liquid phase separation on the crystallization behavior of a poly(ethylene-ran-vinyl acetate) and paraffin wax blend

The effect of liquid-liquid phase separation (LLPS) on the crystallization behavior of poly(ethylene-ran-vinyl acetate) with a vinyl acetate content of 9.5 wt % (EVA-H) in the critical composition of a 35/65 (wt/wt) EVA-H/paraffin wax blend was investigated by small-angle light and X-ray scattering methods and rheometry. This blend exhibited an upper critical solution temperature (UCST) of 98 degrees C, and an LLPS was observed between the UCST and the melting point of 88 degrees C for the EVA-H in the blend. As the duration time in the LLPS region increased before crystallization at 65 degrees C, both the spherulite size and the crystallization rate of the EVA-H increased, but the degree of the lamellar ordering in the spherulite and the degree of crystallinity of the EVA-H in the blend decreased. (C) 2000 John Wiley & Sons, Inc.