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Structural changes induced by thermal treatments on emptied and filled clathrates of syndiotactic polystyrene
Author(s) -
Manfredi Carla,
De Rosa Claudio,
Guerra Gaetano,
Rapacciuolo Mariateresa,
Auriemma Finizia,
Corradini Paolo
Publication year - 1995
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.1995.021960907
Subject(s) - polystyrene , tacticity , polymer chemistry , materials science , thermal , polymer science , chemical engineering , chemistry , composite material , polymer , thermodynamics , polymerization , physics , engineering
The solvent molecules included in the clathrates (δ‐form) of syndiotactic polystyrene (s‐PS) are removed by suitable extraction procedures. An emptied δ‐form is produced which is different from the known γ‐form obtained by heating. The structural changes induced by thermal treatments on emptied and filled clathrates of s‐PS, have been followed by thermogravimetry, X‐ray diffraction analysis, differential scanning calorimetry and Fourier‐transform infrared spectroscopy. It is shown that, under suitable conditions, the emptied clathrates can be transformed into a mesomorphic form, which retains the chains in the helical conformation. This “helical” mesomorphic form, different from the previously known “planar” mesomorphic form, crystallizes by thermal treatments into the “helical” crystalline γ‐form.