Crystallization of CH2-chain molecules condensed from vapor phase

✍ Scribed by Lampe, G. R. ;Hellwege, K.-H.

• Book ID: 104532096
• Publisher: John Wiley and Sons
• Year: 1962
• Weight: 290 KB
• Volume: 57
• Category: Article
• ISSN: 0022-3832
• DOI: 10.1002/pol.1962.1205716532

✦ Synopsis

Abstract

In a high vacuum vessel thin films of n‐paraffins and of decomposition products of polyethylene were condensed on cooled plates of rock salt. The films are amorphous at a condensation temperature of −170°C. Owing to the splitting of the infrared absorption band at 725 cm.^−1^ one can observe the partial crystallization of the film with increasing temperature. Evidently a complete interpretation of the observed absorption bands is not possible by assuming only a doublet due to the crystalline part and a singlet due to the amorphous part. There are intermediate states, the absorption spectrum of which is neither that of the completely amorphous nor that of the completely crystalline material. The amount of material which is in the intermediate phase is about 30% at −170°C.; at room temperature it becomes zero for n‐paraffins and goes down to only a few per cent for technical polyethylenes. By the same method epitaxy and texture at higher temperature can be proved.