The synthesis of a new fully aromatic thermotropic polyester obtained by reaction of terephthalic acid and 2-[4-(acetyloxy)phenyl]-6-(acetyloxy)benzoxazoleis described. A preliminary characterization of the polymer is reported, based on DSC,TGA, X-ray diffraction analysis, optical observations, and dynamic mechanical thermal analysis. The polymer as prepared is a semicrystalline material, with a glass transition of 181"C, that melts at 408 °C to give a liquid crystal phase of probable nematic nature. Relevant chemical decomposition takes place in the temperature range 510-620 °C. A remarkable crystallinity has been observed also in samples obtained by cooling the liquid crystal phase. Fibers were obtained by melt extrusion which show a high degree of macroscopic orientation.
Synthesis and Preliminary Characterization of a New Fully Aromatic Mesogenic Polyester Containing a 2-Phenylbenzoxazole Group / Caruso, Ugo; Centore, Roberto; Roviello, Antonio; A., Sirigu. - In: MACROMOLECULES. - ISSN 0024-9297. - STAMPA. - 25:(1992), pp. 2290-2293.
Synthesis and Preliminary Characterization of a New Fully Aromatic Mesogenic Polyester Containing a 2-Phenylbenzoxazole Group
CARUSO, UGO;CENTORE, ROBERTO;ROVIELLO, ANTONIO;
1992
Abstract
The synthesis of a new fully aromatic thermotropic polyester obtained by reaction of terephthalic acid and 2-[4-(acetyloxy)phenyl]-6-(acetyloxy)benzoxazoleis described. A preliminary characterization of the polymer is reported, based on DSC,TGA, X-ray diffraction analysis, optical observations, and dynamic mechanical thermal analysis. The polymer as prepared is a semicrystalline material, with a glass transition of 181"C, that melts at 408 °C to give a liquid crystal phase of probable nematic nature. Relevant chemical decomposition takes place in the temperature range 510-620 °C. A remarkable crystallinity has been observed also in samples obtained by cooling the liquid crystal phase. Fibers were obtained by melt extrusion which show a high degree of macroscopic orientation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
