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Modifications in the mesogenic unit of poly(oxytetramethyleneoxycarbonyl‐3‐chloro‐1,4‐phenyleneoxyterephthaloyloxy‐2‐chloro‐1,4‐phenylenecarbonyl)
Author(s) -
del Pino Javier,
Gómez Marian A.,
Ellis Gary,
Marco Carlos,
Fatou José G.
Publication year - 1994
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.1994.021950614
Subject(s) - mesogen , mesophase , differential scanning calorimetry , crystallography , polymer , liquid crystal , raman spectroscopy , chemistry , polymer chemistry , materials science , diffraction , organic chemistry , liquid crystalline , optics , thermodynamics , physics , optoelectronics
The effect of asymmetrical chlorine substitution in the mesogenic unit of poly(oxytetramethyleneoxycarbonyl‐3‐chloro‐1,4‐phenyleneoxyterephthaloyloxy‐2‐chloro‐1,4‐phenylenecarbonyl) ( 1 ) has been studied by means of differential scanning calorimetry, optical microscopy and X‐ray diffraction. The polymer presents three‐dimensional ordering, in spite of the substitution, and shows a transition to a nematic mesophase at 274°C and to the isotropic melt at 319°C. As for the unsubstituted polymer poly(oxytetramethyleneoxycarbonyl‐1,4‐phenyleneoxyterephthaloyloxy‐1,4‐phenylenecarbonyl), two different crystalline forms have been observed and some information about their structure has been obtained by Fourier‐Transform Raman spectroscopy and 13 C solid‐state nuclear magnetic resonance. First results indicate that the most important structural differences between both polymorphs occur in the mesogenic unit.