A STUDY OF BLENDS OF ISOTACTIC POLYPROPYLENE WITH HIGH-DENSITY POLYETHYLENE BY TRANSMISSION ELECTRON-MICROSCOPY

Isotactic polypropylene (iPP) was blended with a high-density polyethy lene (HDPE) and the blends, quenched from the melt at temperatures bet ween 170 and 200 degrees C, were examined by looking at surface replic as 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. Thi s ripening can be used to detect phase separation where the driving fo rce is low (i.e. near to phase boundaries). The composition range wher e phase separation is observed decreases gradually with temperature be tween 200 and 170 degrees C. (C) 1998 Published by Elsevier Science Lt d. All rights reserved.