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Diffraction modelling of poly(vinyl chloride): An approach to the crystallinity enigma
Author(s) -
Hobson Rachel J.,
Windle Alan H.
Publication year - 1993
Publication title -
macromolecular theory and simulations
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.37
H-Index - 56
eISSN - 1521-3919
pISSN - 1022-1344
DOI - 10.1002/mats.1993.040020207
Subject(s) - crystallinity , vinyl chloride , diffraction , materials science , polymer chemistry , chemical engineering , polymer science , composite material , polymer , optics , physics , engineering , copolymer
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.