ISSN:
0887-6266
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The mesomorphic transitions, crystallization from the mesophase, and the influence of the specimen preparation method on the solid-state structure of an aromatic polyester containing a triad aromatic ester mesogenic group and a decamethylene flexible spacer in the main chain were studied by DSC, SALS, WAXS, polarizing microscopy, torsional braid analysis, and depolarizing transmittance techniques. The specimens obtained from solution were semicrystalline and exhibited nematic mesophase formation above the melting point Tm, whereas the melt-cast specimens were mesomorphic as cast. A transition from the nematic phase to another mesophase, designated Mx, is proposed to occur below Tm, so this transition is monotropic. It appears that the transition to the Mx mesophase occurs before, and may even be a prerequisite for, crystallization of the melt-cast specimens. The thermal expansion coefficient of the anisotropic melt is close to that of the isotropic melt, and the Tg of the supercooled solid mesophase is close to that of the amorphous phase.
Additional Material:
18 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/polb.1989.090270812
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