Morphology and mechanical properties of blends of linear low density polyethylene and poly(ethenepropene-1-butene)

Blends of linear low density polyethylene (LLDPE) and ethene-propene-1-butene copolymer (t-PP) were obtained through mechanical mixing using a singlescrew extruder with different compositions: 20, 40, 50, 60, and 80 wt % of t-PP. For this, two types of polyethylene were used: 1-hexene comonomer and I-octene comonomer based. The same blends were prepared in a batch mixer and the torque and temperature were analyzed. The torque showed a decrease with increasing t-PP content, indicating better processability of the mixture in comparison with LLDPE. The morphology of the blends was analyzed by SEM and showed a composition dependence. The mechanical properties of the blends were evaluated by tensile tests. The results revealed that the best properties were obtained in a 20% t-PP blend. (c) 2006 Wiley Periodicals, Inc.