Diffraction modelling of poly(vinyl chloride): An approach to the crystallinity enigma

✍ Scribed by Hobson, Rachel J. ;Windle, Alan H.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1993
• Weight: 275 KB
• Volume: 2
• Category: Article
• ISSN: 1018-5054
• DOI: 10.1002/mats.1993.040020207

✦ Synopsis

Abstract

This paper demonstrates that changes which are seen to occur in experimental X‐ray diffraction patterns of poly(vinyl chloride) (PVC) with varying sample tacticity are indicative of a crystal structure in which both isotactic and syndiotactic sequences are incorporated within the same lattice. The isotactic sequences are in a conformation first suggested by Juijn et al. which enables them to emulate the shape of the syndiotactic chain. We present a short summary of molecular and diffraction modelling results which show how the intensities of the 200 and 110 peaks change with crystallite tacticity. The results provide a rational explanation for the long standing enigma that the observed crystallinity of atactic PVC is too high to be accounted for in terms of crystallization of syndiotactic sequences only.