DIRECT OBSERVATIONS OF INTERLAMELLAR CRYSTALLIZATION IN LINEAR POLYETHYLENE

The crystallization of oriented polyethylene films is followed by transmission electron microscopy (TEM) operated in the defocus-contrast mode. Crystalline lamellae grow with gaps of amorphous material between each lamella, the thickness of which is very irregular in the beginning. At a later stage of crystallization, new crystallites nucleate and grow within the gaps. In a successive thickening process the crystalline lamellae consume the crystallites and the morphology appears as a regular stacking of crystalline lamellae and amorphous interlayers. These processes are independent of molecular weight distribution. © 1979, Taylor & Francis Group, LLC. All rights reserved.