Influence of comonomer incorporation on morphology and thermal and mechanical properties of blends based upon isotactic metallocene-polypropene and random ethene/1-butene copolymers

Blends of isotactic polypropene (i-PP) with random ethene/1-butene (EB) copolymers containing 10, 24, 48, 58, 62, 82, and 90 wt % 1-butene were prepared in order to examine the influence of the EB molecular architecture on the morphology development as well as on the thermal and mechanical properties. Compatibility between i-PP and EB increased with increasing 1-butene content in EB to afford single-phase blends at a 1-butene content exceeding 82 wt %. The morphology was investigated using AFM and TEM. Improved compatibility accounted for enhanced EB dispersion and interfacial adhesion. Highly flexible as well as stiff blends with improved toughness were obtained. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 838–848, 1999