화학공학소재연구정보센터
Journal of Polymer Science Part A: Polymer Chemistry, Vol.33, No.2, 189-196, 1995
Characterization of a Melt Processable Liquid-Crystal Copolyester
Poly[oxy(2-methyl-1,4-phenylene) oxyterephthaloyl-co-oxymethylene-1,4-cyclohexylene- methyleneoxyterephthaloyl] was synthesized using a solution-based process. This copolyester has cyclohexylene dimethylene as a semi-rigid spacer along the polymer main chain to interrupt the inherent rigidity of the system while preserving the mesogenicity of the macromolecules. Polymer characterization includes elemental analysis, Fourier transform infrared spectroscopy, nuclear magnetic resonance, hot-stage polarized light microscopy, wide-angle x-ray diffraction, dilute solution viscometry, differential scanning calorimetry, and thermogravimetric analysis. This copolyester shows nematic liquid crystalline behavior in polarized light above about 240 degrees C. The intrinsic and inherent viscosities are 0.88 and 0.68 dL/g respectively. The observed melting temperature of this copolyester is about 265 degrees C, but melting begins as low as 215 degrees C, making the polymer readily melt-processable. The degradation temperature is about 340 degrees C under a nitrogen atmosphere.