Linear Polyethylene/Polypropylene/Ethylene-Propylene Copolymer Ternary Blends: II. Relationship Between Mechanical Properties and Morphology

Abstract

From a mechanical point of view, high density polyethylene (HDPE)/isotactic polypropylene (iPP) blend have generally been considered as very unsatisfactory materials^1,3. In particular, they show very poor ultimate mechanical properties at room temperature in comparison with those of the blend constituents. This fact precludes their use for most commercial purposes. In previous papers^4,5 we found that it is possible to improve the mechanical tensile performance of these blends by appropriately varying the testing conditions such as the temperature and the drawing rate. In this way even ultradrawn blend fibers with high modulus and strength could be easily obtained, just as in the case of pure polyolefins.