Further electronmicroscope observations on polyethylene II. An artifact makes amorphous surface layers visible on crystal lamellae in melts

Abstract

The granule structure that occurs when a polyethylene melt is stained with chlorosulfonic acid by a rapid technique, e.g. at 150°C, cannot be ascribed to nodules. In Part I of this study, it was unmasked as an artifact caused by microdemixing [1]. However, demixing can be prevented by first crosslinking the melt by electron beams. In this case, the melt appears to be homogeneously black after staining. If melting of crystalline polyethylene is arrested exactly at 134°C by the rapid method, not only can the granule structure of the original melt be recognized in the ultrathin section, but also very thin black layers can be seen on the surfaces of the lamellae. Their character is apparently that of a crosslinked melt and they, therefore, conform more to the switchboard model than to the regularly adjacent re-entry model.