| Abstract: | Polyoxy(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°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°C, but melting begins as low as 215°C, making the polymer readily melt-processable. The degradation temperature is about 340°C under a nitrogen atmosphere. © 1995 John Wiley & Sons, Inc. |
