ISSN:
1022-1352
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
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.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1995.021960907
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