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 o f 9.5 wt % (EVA-H) in the critical composition of a 35/65 (wt/wt) EVA-H/par affin wax blend was investigated by small-angle light and X-ray scattering methods and rheometry. This blend exhibited an upper critical solution temp erature (UCST) of 98 degrees C, and an LLPS was observed between the UCST a nd the melting point of 88 degrees C for the EVA-H in the blend. As the dur ation time in the LLPS region increased before crystallization at 65 degree s C, both the spherulite size and the crystallization rate of the EVA-H inc reased, but the degree of the lamellar ordering in the spherulite and the d egree of crystallinity of the EVA-H in the blend decreased. (C) 2000 John W iley & Sons, Inc.