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Structures in polystyrene solutions: Their origins and their implications on physical gelation
Author(s) -
Guenet JeanMichel,
Klein Marc
Publication year - 1990
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19900390108
Subject(s) - tacticity , polystyrene , polymer , intercalation (chemistry) , solvent , materials science , polymer chemistry , melting point , crystallography , chemical engineering , chemical physics , chemistry , composite material , organic chemistry , polymerization , engineering
From studies on dilute and semi‐dilute solutions it will be shown that gelation in atactic polystyrene proceeds via the creation of a nematic‐like order (formation of a polymer‐solvent intercalate with the highly syndiotactic sequences). A similar mechanism holds for isotactic polystyrene (intercalate wherein the chain adopts a near‐3 1 helical form). It will be emphasized that the gelation phenomenon depends upon both the solvent size and the volume of the cavities created by the phenyl groups along the chain. Finally, diffraction experiments on well‐organized structures (giant spherolites of 150–200/μm diameter) grown from isotactic polystyrene solutions and possessing the same melting point as the gel show the absence of 12 1 helices. Therefore, gel formation is not due to the growth of this helical form.