Large polyethylene crystals formed under high pressure

TLDR: In this article, it was shown that the thickness of polyethylene extended-chain crystals depends largely on the conditions of crystallization and the characteristics of the sample, and it was generally accepted that the length of the lamellae did not exceed the molecular length.

Abstract: It is well known that the molecular chain of polyethylene becomes extended by crystallization under high pressure [1-4]. The extended-chain crystals consist of lamellae whose thickness is more than 0.2 μm. The thickness of the crystals depends largely on the conditions of crystallization and the characteristics of the sample. Most observations on the thickness of the extended-chain crystals reported values of 1 to 2 pm by electron microscopy, but, under suitable conditions, thicknesses up to 3 pm were obtained [1]. In these reports it was generally accepted that the thickness of the lamellae did not exceed the molecular length.