Abstract: The morphology of highly oriented melt-drawn films of iPP/HDPE blends has beeninvestigated by TEM and DSC. Both the HDPE and the iPP in the films consist of hig-hly oriented crystalline lamellae. Blending iPP with HDPE results in decrease of crystalline width and melting point of HDPE, as well as the change of HDPE texture from asingle crystal texture to fibre symmetric structure. No marked phases of iPP were foundin the films at low iPP contents(<20%). Individual phases of iPP were observed at iPPcontents>30%.There is no sharp boundary between the two phases. The lamellae of HDPEand iPP in the boundary region are higher interpenetrating or connecting each other. When the preparation temperature of the film is higher(135-140℃)and the content ofHDPE in the blends is below 30%, epitaxial growth of HDPE lamellae on highly orientediPP lamellae has been observed. The intercrossing angle of the two kinds of epitaxial lamellae is about 45°-50°, while the contact planes are(010)of iPP and(100)of HDPE.

Key words: polypropylene, polyethylene, blends, morphology, epitaxy