POLYPROPYLENE BLENDS WITH A PHENOXY

Polypropylene (PP) blends with a phenoxy have been prepared in various compositions using a Brabender Plasticorder. Scanning electron micros copy (SEM) micrographs showed a clean two-phase morphology. The domain s were larger when PP formed the dispersed phase, probably due to the greater melt viscosity of PP. The melting peak temperature (T-m) of PP decreased marginally, whereas the glass transition temperature (T-g) of phenoxy increased by 5-10 degrees C, in the blends. X-ray diffracti on measurements indicated that PP crystallizes in a hexagonal beta-for m in 50/50 and 30/70 (PP/phenoxy) blends. Mechanical properties of the blends generally showed negative deviation from the additivity rule, perhaps due to the inherently immiscible nature of the blends. (C) 199 6 John Wiley & Sons, Inc.