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Syndiotactic polystyrene/ethylbenzene complex: Chain conformations and phase behaviour
Author(s) -
Spells Stephen J.
Publication year - 1997
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19971140108
Subject(s) - tacticity , polystyrene , radius of gyration , polymer , materials science , ethylbenzene , phase (matter) , polymer chemistry , neutron scattering , small angle x ray scattering , annealing (glass) , solvent , toluene , thermodynamics , crystallography , scattering , analytical chemistry (journal) , chemistry , polymerization , organic chemistry , composite material , physics , optics
Syndiotactic polystyrene (sPS) has been studied, primarily in the δ (solvent‐stabilised) and γ phases. Crystallisation from dilute ethylbenzene solution at 40°C leads to a lamellar morphology, with a similar unit cell for the polymer/solvent complex as that proposed by Chatani et al for the sPS/toluene complex [1]. As the temperature is raised, the X‐ray long period increases in the temperature range of decomplexation, becoming constant in the y phase before increasing again on annealing in the α phase. Neutron scattering measurements show negligible isotopic fractionation and only a small increase in the radius of gyration in the plane of the sedimented δ phase mats (R xy ) with increasing molecular weight. Together with model simulations which reproduce satisfactorily both the form of Kratky plots and the values for R xy , this evidence points strongly towards a sheetlike structure (as is obtained for other non‐complexing solution‐grown polymer crystals). Increases in R xy and changes in the scattering curves from those characteristic of sheetlike structures in the γ phase are interpreted as indicating movement of crystal stems out of the sheets.