Rheological and morphological properties of high-density polyethylene and poly(ethylene-octene) blends

The rheological and morphological properties of blends based on high-density polyethylene (HDPE) and a commercial ethylene-octene copolymer (EOC) produced by metallocene technology were investigated. The rheological properties were evaluated in steady and dynamic shear experiments at 190degreesC in shear rates ranging from 90 s(-1) to 1500 s(-1) and frequency range between I rad/s and 10(2) rad/s, respectively. These blends presented a high level of homogeneity in the molten state and rheological behavior was generally intermediate to those of the pure components. Scanning electron microscopy (SEM) showed that the blends exhibit dispersed morphologies with EOC domains distributed homogeneously and with particle size inferior to 2 mum. (C) 2002 Wiley Periodicals, Inc.