Polymer, Vol.39, No.25, 6669-6672, 1998
A study of blends of isotactic polypropylene with high density polyethylene by transmission electron microscopy
Isotactic polypropylene (iPP) was blended with a high-density polyethylene (HDPE) and the blends, quenched from the melt at temperatures between 170 and 200 degrees C, were examined by looking at surface replicas in a transmission electron microscope. Widespread phase separation was evident and a range of morphologies recorded. Phase ripening takes place progressively with time as the blends are held in the melt. This ripening can be used to detect phase separation where the driving force is low (i.e. near to phase boundaries). The composition range where phase separation is observed decreases gradually with temperature between 200 and 170 degrees C.
Keywords:LIQUID-PHASE-SEPARATION;BRANCHED POLYETHYLENES;COPOLYMERS;SEGREGATION;MELTS;BEHAVIOR;DIAGRAM