STEREOBLOCK POLYPROPYLENE ISOTACTIC POLYPROPYLENE BLENDS .1. PHASE ORGANIZATION

The phase organization of stereoblock polypropylene/isotactic polypropylene blends has been analyzed. The different samples were prepared by a two-stage process, that is, solvent casting followed by pressure molding. The analysis was carried out using techniques such as X-ray diffraction, differential scanning calorimetry (DSC), and thermomicroscopy. The experimental results show that both the components segregate a crystalline phase and that the overall crystallinity, as well as the crystallinity of each component, is affected by the sample composition. Some evidence of co-crystallization, at least for samples at low content in isotactic polypropylene, has been found. (C) 1994 John Wiley and Sons, Inc.