Abstract: A study of the effect of thermal treatment on epitaxial crystallization in HDPE/iPPblends was carried out by means of TEM and specimen tilt technique of electron microscopy. When the solution-cast films of HDPE/iPP blends were heated to above the meltingpoint of HDPE(145℃)for about 30 min., and subsequently cooled to room temperature, thesize of the recrystallized lamellae of HDPE increased in both regions of the cross-hatchedand single-crystal-type structure of iPP. However, the epitaxial and structural relationshipsbetween HDPE and iPP remained unchanged. Under the heat treatment of higher temperature(194℃,20 min.), the morphologies and structures of recrystallized HDPE and iPP in theblend were similar to that of the blend heat-treated at lower temperature(145℃).

Key words: polypropylene, polyethylene, blend, epitaxial crystallization, morphological structure